gogeshop's Blog

Digital rights management (DRM) is a term for access control technologies that can be used by hardware manufacturers, publishers, copyright holders and individuals to limit the usage of digital content and devices. The term is used to describe any technology that inhibits uses of digital content not desired or intended by the content provider (Dell XPS M1210 Battery) http://www.hdd-shop.co.uk .

The term does not generally refer to other forms ofcopy protection which can be circumvented without modifying the file or device, such as serial numbers or keyfiles. It can also refer to restrictions associated with specific instances of digital works or devices    (Dell Studio XPS 1340 Battery)     .

Digital rights management is used by companies such as Sony, Amazon, Apple Inc., Microsoft, AOL and the BBC  .

The use of digital rights management is controversial. Proponents argue it is needed by copyright holders to prevent unauthorized duplication of their work, either to maintain artistic integrity or to ensure continued revenue streams    (Dell Studio XPS 1640 Battery)    .

Some opponents, such as the Free Software Foundation (through its Defective By Design campaign), maintain that the use of the word "rights" is misleading and suggest that people instead use the term digital restrictions management. Their position is essentially that copyright holders are restricting the use of material in ways that are beyond the scope of existing copyright laws (Dell Vostro 1710 Battery) ,

and should not be covered by future laws. The Electronic Frontier Foundation, and other opponents, also consider DRM systems to be anti-competitive practices. This position holds that the rights of the user need legal protection  (Sony VGP-BPS13 battery)   .

Introduction

DRM technologies attempt to control use of digital media by preventing access, copying or conversion to other formats by end users. Long before the arrival of digital or even electronic media, copyright holders, content producers, or other financially or artistically interested parties had business and legal objections to copying technologies    (Sony VGP-BPS13/B battery)   .

Examples include: player piano rolls early in the 20th century, audio tape recording, and video tape recording(e.g., the "Betamax case" in the U.S.). Copying technology thus exemplifies a disruptive technology     (Sony VGP-BPS13/S battery)    .

The advent of digital media and analog/digital conversion technologies, especially those that are usable on mass-market general-purpose personal computers, has vastly increased the concerns of copyright-dependent individuals and organizations, especially within the music and movie industries   (Sony VGP-BPS13A/B battery)  ,

because these individuals and organizations are partly or wholly dependent on the revenue generated from such works. While analog media inevitably loses quality with each copy generation, and in some cases even during normal use, digital media files may be duplicated an unlimited number of times with no degradation in the quality of subsequent copies (Sony VGP-BPS13B/B battery) .

The advent of personal computers as household appliances has made it convenient for consumers to convert media (which may or may not be copyrighted) originally in a physical/analog form or a broadcast form into a universal, digital form (this process is called ripping) for location- or timeshifting      (Sony VGP-BPS13B/B battery)      .

This, combined with the Internet and popular file sharing tools, has made unauthorized distribution of copies of copyrighted digital media (digital piracy) much easier.

DRM technologies have enabled publishers to enforce access policies that not only disallow copyright infringements   (Sony VGP-BPL9 battery)     ,

but also prevent lawful fair use of copyrighted works, or even implement use constraints on non-copyrighted works that they distribute; examples include the placement of DRM on certain public-domain or open-licensed e-books, or DRM included in consumer electronic devices that time-shift (and apply DRM to) both copyrighted and non-copyrighted works   (Sony VGP-BPL11 battery)      .

DRM is most commonly used by the entertainment industry (e.g., film and recording). Many online music stores, such as Apple Inc.'s iTunes Store, as well as many e-book publishers have implemented DRM    (Sony VGP-BPL15 battery)      .

In recent years, a number of television producers have implemented DRM on consumer electronic devices to control access to the freely-broadcast content of their shows, in response to the rising popularity of time-shifting digital video recorder systems such as TiVo     (Dell Inspiron E1505 battery)  .

Technologies

DRM and film

An early example of a DRM system was the Content Scrambling System (CSS) employed by the DVD Forum on film DVDs since ca. 1996     (Dell Latitude E6400 battery)      .

CSS used a simple encryption algorithm, and required device manufacturers to sign license agreements that restricted the inclusion of features, such as digital outputs that could be used to extract high-quality digital copies of the film, in their players. Thus, the only consumer hardware capable of decoding DVD films was controlled       (HP Pavilion dv6000 Battery)     ,

albeit indirectly, by the DVD Forum, restricting the use of DVD media on other systems until the release of DeCSS by Jon Lech Johansen in 1999, which allowed a CSS-encrypted DVD to play properly on a computer using Linux, for which the Alliance had not arranged a licensed version of the CSS playing software     (Sony Vaio VGN-FZ31S battery)    .

Microsoft's Windows Vista contains a DRM system called the Protected Media Path, which contains the Protected Video Path (PVP). PVP tries to stop DRM-restricted content from playing while unsigned software is running in order to prevent the unsigned software from accessing the content       (Sony VGN-FZ31S battery)       .

Additionally, PVP can encrypt information during transmission to the monitor or the graphics card, which makes it more difficult to make unauthorized recordings.

Advanced Access Content System (AACS) is a DRM system for HD DVD and Blu-ray Discs developed by the AACS Licensing Administrator      (Hp pavilion dv6000 battery)       ,

LLC (AACS LA), a consortium that includes Disney, Intel, Microsoft, Matsushita (Panasonic), Warner Brothers, IBM, Toshiba and Sony. In December 2006 a process key was published on the internet byhackers, enabling unrestricted access to AACS-restricted HD DVD content. After the cracked keys were revoked, further cracked keys were released     (SONY VGN-FZ38M Battery)       .

DRM and television

The CableCard standard is used by cable television providers in the United States to restrict content to services to which the customer has subscribed        (SONY VGN-FZ31z Battery)     .

The broadcast flag concept was developed by Fox Broadcasting in 2001 and was supported by the MPAA and the U.S. Federal Communications Commission (FCC). A ruling in May 2005 by a US Court of Appeals held that the FCC lacked authority to impose it on the TV industry in the US      (Sony VGN-FZ31Z Battery)       .

It required that all HDTVs obey a stream specification determining whether or not a stream can be recorded. This could block instances of fair use, such as time-shifting. It achieved more success elsewhere when it was adopted by the Digital Video Broadcasting Project (DVB), a consortium of about 250 broadcasters, manufactures, network operators, software developers, and regulatory bodies from about 35 countries involved in attempting to develop new digital TV standards        (SONY VGN-FZ31E Battery)   .

An updated variant of the broadcast flag has been developed in the Content Protection and Copy Management (DVB-CPCM). It was developed in private, and the technical specification was submitted to European governments in March 2007. As with much DRM, the CPCM system is intended to control use of copyrighted material by the end-user, at the direction of the copyright holder  (SONY  VGN-FZ31J Battery)       .

According to Ren Bucholz of the EFF, which paid to be a member of the consortium, "You won't even know ahead of time whether and how you will be able to record and make use of particular programs or devices". The DVB supports the system as it will harmonize copyright holders' control across different technologies and so make things easier for end users        (SONY VGN-FZ31M Battery)    .

The normative sections have now all been approved for publication by the DVB Steering Board, and will be published by ETSI as a formal European Standard as ETSI TS 102 825-X where X refers to the Part number of specification       (SONY VGN-FZ31B Battery) .

Nobody has yet stepped forward to provide a Compliance and Robustness regime for the standard (though several are rumoured to be in development), so it is not presently possible to fully implement a system, as there is nowhere to obtain the necessary device certificates   (SONY VGP-BPS13 Battery)         .

DRM and music

Audio CDs

Discs with digital rights management schemes are not legitimately standards-compliant Compact Discs (CDs) but are rather CD-ROM media. Therefore they all lack the CD logotype found on discs which follow the standard (known as Red Book)     (Dell Inspiron 1320 Battery)     .

Therefore these CDs could not be played on all CD players. Many consumers could also no longer play purchased CDs on their computers. Personal computers running Microsoft Windows would sometimes even crash when attempting to play the CDs.

In 2005, Sony BMG introduced new DRM technology which installed DRM software on users' computers without clearly notifying the user or requiring confirmation       (Dell Inspiron 1320n Battery)     .

Among other things, the installed software included a rootkit, which created a severe security vulnerability others could exploit. When the nature of the DRM involved was made public much later, Sony initially minimized the significance of the vulnerabilities its software had created, but was eventually compelled to recall millions of CDs, and released several attempts to patch the surreptitiously included software to at least remove the rootkit       (Dell Inspiron 1464 Battery)    .

Several class action lawsuits were filed, which were ultimately settled by agreements to provide affected consumers with a cash payout or album downloads free of DRM.

Sony's DRM software actually had only a limited ability to prevent copying, as it affected only playback on Windows computers, not on other equipment      (Dell Inspiron 1564 Battery)      .

Even on the Windows platform, users regularly bypassed the restrictions. And, while the Sony DRM technology created fundamental vulnerabilities in customers' computers, parts of it could be trivially bypassed by holding down the "shift" key while inserting the CD, or by disabling the autorun feature     (Dell Inspiron 1764 Battery)     .

In addition, audio tracks could simply be played and re-recorded, thus completely bypassing all of the DRM (this is known as the analog hole). Sony's first two attempts at releasing a patch which would remove the DRM software from users' computers failed.

In January 2007, EMI stopped publishing audio CDs with DRM, stating that "the costs of DRM do not measure up to the results    (Dell Studio 1450 Battery)   .

"Following EMI, Sony BMG was the last publisher to abolish DRM completely, and audio CDs containing DRM are no longer released by the four record labels.

Internet music

Many online music stores employ DRM to restrict usage of music purchased and downloaded online    (Dell Studio 1457 Battery) .

There are many options for consumers wishing to purchase digital music over the internet:

• The iTunes Store (run by Apple), allows users to purchase a track online. The tracks purchased use Apple's FairPlay DRM system. Apple later launched iTunes Plus, which offered higher quality DRM-free tracks for a higher price. On October 17, 2007, iTunes Plus became available at the usual US$0.99 price, replacing the non-Plus tracks  (Dell Latitude D610 Battery) .
• On January 6, 2009 Apple announced at its Macworld Expo keynote that iTunes music would be available completely DRM free by the end of the month. Videos sold and rented through iTunes, as well as mobile software sold through the iTunes App Store for the iPhone and iPod touch, continue to use Apple's FairPlay DRM to inhibit casual copying  (Toshiba NB100 Battery) .
• Apple increased the price of many hit singles and selected classic tracks to $1.29 on April 7, 2009.

• Napster music store offers a subscription-based approach to DRM alongside permanent purchases       (Toshiba Satellite M65 battery) .
• Users of the subscription service can download and stream an unlimited amount of music transcoded to Windows Media Audio (WMA) while subscribed to the service. But when the subscription period lapses, all of the downloaded music is unplayable until the user renews his or her subscription    (Toshiba Satellite M60 battery)       .
• Napster also charges users who wish to use the music on their portable device an additional $5 per month. In addition, Napster gives users the option of paying an additional $0.99 per track to burn it to CD or for the song to never expire. Music bought through Napster can be played on players carrying the Microsoft PlaysForSure logo (which, notably, do not include iPods or even Microsoft's own Zune)       (Dell Latitude D830 Battery)  .
• As of June 2009 Napster is giving DRM free MP3 music, which can be played on iPhones and iPods.

• Wal-Mart Music Downloads, another online music download store, charges $0.94 per track for all non-sale downloads. All Wal-Mart, Music Downloads are able to be played on any Windows PlaysForSure marked product      (Dell Latitude D620 Battery)   .
• The music does play on the SanDisk's Sansa mp3 player, for example, but must be copied to the player's internal memory. It cannot be played through the player'smicroSD card slot, which is a problem that many users of the mp3 player experience (Dell Studio 1735 Battery)   .

• Sony operated an online music download service called "Connect" which used Sony's proprietary OpenMG DRM technology. Music downloaded from this store (usually via Sony's SonicStagesoftware) was only playable on computers running Microsoft Windows and Sony hardware (including the PSP and some Sony Ericsson phones)    (Dell Inspiron Mini 10 Battery)   .

• Kazaa is one of a few services offering a subscription-based pricing model. However, music downloads from the Kazaa website are DRM-protected, and can only be played on computers or portable devices running Windows Media Player, and only as long as the customer remains subscribed to Kazaa        (Sony VGN-FW11S Battery)      .

The various services are currently not interoperable, though those that use the same DRM system (for instance the several Windows Media DRM format stores, including Napster, Kazaa and Yahoo Music) all provide songs that can be played side-by-side through the same player program       (Sony VGN-FW11M Battery)     .

Almost all stores require client software of some sort to be downloaded, and some also need plug-ins. Several colleges and universities, such as Rensselaer Polytechnic Institute, have made arrangements with assorted Internet music suppliers to provide access (typically DRM-restricted) to music files for their students       (Dell Studio 1555 battery)    ,

to less than universal popularity, sometimes making payments from student activity fee funds. One of the problems is that the music becomes unplayable after leaving school unless the student continues to pay individually. Another is that few of these vendors are compatible with the most common portable music player, the Apple iPod    (Dell Latitude E5400 Battery)    .

The Gowers Review of Intellectual Property (to HMG in the UK; 141 pages, 40+ specific recommendations) has taken note of the incompatibilities, and suggests (Recommendations 8—12) that there be explicit fair dealing exceptions to copyright allowing libraries to copy and format-shift between DRM schemes, and further allowing end users to do the same privately       (Dell Latitude E4200 Battery)     .

If adopted, some of the acrimony may decrease.

Although DRM is prevalent for Internet music, some online music stores such as eMusic, Dogmazic, Amazon, and Beatport, do not use DRM despite encouraging users to avoid sharing music    (Dell Vostro A840 Battery)      .

Another online retailer, Xiie.net, which sells only unsigned artists, encourages people to share the music they buy from the site, to increase exposure for the artists themselves. Major labels have begun releasing more online music without DRM  (Dell Inspiron 300M Battery)    .

Eric Bangeman suggests in Ars Technica that this is because the record labels are "slowly beginning to realize that they can't have DRMed music and complete control over the online music market at the same time... One way to break the cycle is to sell music that is playable on any digital audio player     (Dell Studio 1737 battery)    .

eMusic does exactly that, and their surprisingly extensive catalog of non-DRMed music has vaulted it into the number two online music store position behind the iTunes Store." Apple's Steve Jobs has called on the music industry to eliminate DRM in an open letter titled Thoughts on Music      (Dell Inspiron E1505 battery)    .

Apple's iTunes store will start to sell DRM-free 256 kbit/s (up from 128 kbit/s) AAC encoded music from EMI for a premium price (this has since reverted to the standard price). In March 2007, Musicload.de, one of Europe's largest online music retailers, announced their position strongly against DRM        (Dell Latitude E6400 battery)     .

In an open letter, Musicload stated that three out of every four calls to their customer support phone service are as a result of consumer frustration with DRM.

Computer games

Computer games sometimes use DRM technologies to limit the number of systems the game can be installed on by requiring authentication with an online server    (Dell RM791 battery)     .

Most games with this restriction allow three or five installs, although some allow an installation to be 'recovered' when the game is uninstalled. This not only limits users who have more than three or five computers in their homes (seeing as the rights of the software developers allow them to limit the number of installations)     (Dell XPS M1530 battery)     ,

but can also prove to be a problem if the user has to unexpectedly perform certain tasks like upgrading operating systems or reformatting the computer's hard drive, tasks which, depending on how the DRM is implemented, count a game's subsequent reinstall as a new installation, making the game potentially unusable after a certain period even if it is only used on a single computer   (Dell XPS M2010 battery)     .

In mid-2008, the publication of Mass Effect marked the start of a wave of titles primarily making use of SecuROM and Steam for DRM and requiring authentication via an online server. The use of DRM scheme in 2008's Spore backfired and there were protests, resulting in a considerable number of users seeking a pirated version instead      (Dell Vostro 1000 battery)   .

This backlash against 3 activation limit was a significant factor in Spore becoming the most pirated game in 2008.

Many mainstream publishers continued to rely on online-based DRM throughout the later half of 2008 and early 2009, including Electronic Arts, Ubisoft and Atari   (Acer Aspire One battery) .

Ubisoft broke with the tendency to use online DRM in late 2008 with the release of Prince of Persia as an experiment to "see how truthful people really are"  regarding the claim that DRM was inciting people to use pirated copies    (Toshiba Satellite P10 Battery) .

Although Ubisoft has not commented on the results of the 'experiment', the majority of their subsequent titles in 2009 contained no online-based DRM since the release of Prince of Persia - notable examples being Anno 1404 and James Cameron's Avatar: The Gamemaking use of the online version of the TAGES copy protection system      (SONY VGN-FZ210CE Battery)    .

An official patch has since been released stripping Anno 1404 of the DRM. Electronic Arts followed suit in June 2009 with The Sims 3,  with subsequent EA and EA Sports titles also being devoid of online DRM.

Ubisoft formally announced a return to on-line authentication on 9 February 2010 through its Uplay on-line gaming platform, starting with Silent Hunter 5, The Settlers 7 and Assassin's Creed 2  (Dell Precision M70 Battery)    .

Silent Hunter V was first reported to have been compromised within 24 hours of release, but users of the cracked version soon found out that only early parts of the game were playable.The Uplay system works by having the installed game on the local PCs incomplete and then continuously downloading parts of the game-code from Ubisoft's servers as the game progresses  (Toshiba Satellite L305 Battery)     ,

making cracking games using the system a daunting task. It was only more than a month after the PC release in the first week of April that software was released that could bypass Ubisoft's DRM in Assassin's Creed 2, demonstrating its strength. The software did this by emulating a Ubisoft server for the game    (Toshiba Satellite T4900 Battery)    .

Later that month, a real crack was released that was able to remove the connection requirement altogether. No fully working crack for Silent Hunter V has been confirmed.

In early March, 2010, Uplay servers suffered a period of inaccessibility due to a large scale DDoS attack, causing around 5% of game owners to become locked out of playing their game    (Toshiba PA3399U-2BRS battery)       .

The company later credited owners of the affected games with a free download, and there has been no further downtime.

Some most prominent cases making use of online DRM technology SecuROM include Spore, BioShock, Mass Effect and Gears Of War (Toshiba Satellite A200 Battery) .

E-books

Electronic books read on a personal computer or an e-book reader typically use DRM restrictions to limit copying, printing, and sharing of e-books. E-books are usually limited to a certain number of reading devices and some e-publishers prevent any copying or printing        (Toshiba Satellite 1200 Battery)     .

Some commentators believe that DRM is something that makes E-book publishing complex .

There are four main ebook formats at present. Mobipocket, Topaz, ePub and PDF. The Amazon Kindle uses both Mobipocket and Topaz format ebooks. Other ebook readers mostly use ePub format ebooks, but with differing DRM schemes    (Toshiba Satellite M300 Battery)     .

There are four main ebook DRM schemes at present, one each from Adobe, Apple, Barnes & Noble and Amazon. Adobe's Adept DRM is applied to ePubs and PDFs, and can be read by several third-party ebook readers, as well as Adobe's Adobe Digital Editions software       (WD  passport essential (500GB/640GB) .

Apple's Fairplay DRM is applied to ePubs,and can currently only be read by Apple's iBooks app on iOS devices. Barnes & Noble's DRM scheme is implemented by Adobe, and is applied to ePubs and the older Palm format ebooks. Amazon's DRM is an adaption of the original Mobipocket encryption, and is applied to Amazon's Mobipocket and Topaz format ebooks (WD   passport essential (250GB/320GB) .

Two software programs to view e-books are Adobe Reader and Microsoft Reader.Each program uses a slightly different approach to DRM. The first version of Adobe Acrobat e-book Reader to have encryption technologies was version 5.05. In the later version 6.0, the technologies of the PDF reader and the e-book reader were combined (WD  passport essential SE (750GB/1TB) ,

allowing it to read both DRM-restricted and unrestricted files.After opening the file, the user is able to view the rights statement, which outlines actions available for the specific document. For example, for a freely transferred PDF, printing, copying to the clipboard, and other basic functions are available to the user      (WD  passport elite(250GB/320GB) .

However, when viewing a more highly restricted e-book, the user is unable to print the book, copy or paste selections. The level of restriction is specified by the publisher or distribution agency.

Microsoft Reader, which exclusively reads e-books in a .lit format, contains its own DRM software      (WD  passport elite(500GB/640GB) .

In Microsoft Reader there are three different levels of access control depending on the e-book: sealed e-books, inscribed e-books and owner exclusive e-books. Sealed e-books have the least amount of restriction and only prevents the document from being modified    (WD  passport studio for Mac(320GB/500GB) .

Therefore, the reader cannot alter the content of the book to change the ending, for instance. Inscribed e-books are the next level of restriction. After purchasing and downloading the e-book, Microsoft Reader puts a digital ID tag to identify the owner of the e-book  (WD  passport studio for Mac(500GB/640GB) .

Therefore, this discourages distribution of the e-book because it is inscribed with the owner’s name making it possible to trace it back to the original copy that was distributed. Other e-book software uses similar DRM schemes. For example, Palm Digital Media, now known as Ereader, links the credit card information of the purchaser to the e-book copy in order to discourage distribution of the books     (WD  Elements series(250GB/320GB) .

The most stringent form of security that Microsoft Reader offers is called owner exclusive e-books, which uses traditional DRM technologies. To buy the e-book the consumer must first open Microsoft Reader, which ensures that when the book is downloaded it becomes linked to the computer’s Microsoft Passport account       (WD  Elements SE(500GB/640GB) .

Thus the e-book can only be opened with the computer with which it was downloaded, preventing copying and distribution of the text.

Amazon.com has remotely deleted purchased copies of George Orwell's 1984 and Animal Farm from customer's Amazon Kindles (WD External HDD ---Elements SE(750GB/1TB) .

Commenters have widely described these actions as Orwellian, and have alluded to Big Brother from Orwell's 1984.After an apology from Amazon CEO Jeff Bezos, the Free Software Foundation has written that this is just one more example of the excessive power Amazon has to remotely censor what people read through its software, and called upon Amazon to free its e-book reader and drop DRM      (WD  Elements desktop(500GB/640GB) .

DRM and documents

Enterprise digital rights management (E-DRM or ERM) is the application of DRM technology to the control of access to corporate documents such as Microsoft Word, PDF, and AutoCAD files, emails, and intranet web pages rather than to the control of consumer media      (WD  Elements desktop(750GB/1TB) .

E-DRM, now more commonly referenced as IRM (Information Rights Management), is generally intended to prevent the unauthorized use (such as industrial or corporate espionage or inadvertent release) of proprietary documents. IRM typically integrates with content management system software      (WD  Elements desktop(1.5 TB/2TB) .

DRM has been used by organizations such as the British Library in its secure electronic delivery service to permit worldwide access to substantial numbers of rare (and in many cases unique) documents which, for legal reasons, were previously only available to authorized individuals actually visiting the Library's document centre at Boston Spa in England  (WD  passport essential SE (750GB/1TB)--USB 3.0)     .

Watermarks

Digital watermarks are features of media that are added during production or distribution. Digital watermarks involve data that is arguably steganographically embedded within the audio or video data.

Watermarks can be used for different purposes that may include     (WD  passport essential (500GB/640GB) :

• recording the copyright owner
• recording the distributor
• recording the distribution chain
• identifying the purchaser of the music   (WD  passport for Mac(320GB/500GB)

Watermarks are not complete DRM mechanisms in their own right, but are used as part of a system for Digital Rights Management, such as helping provide prosecution evidence for purely legal avenues of rights management, rather than direct technological restriction     (WD  passport for Mac(640GB/1TB) .

Some programs used to edit video and/or audio may distort, delete, or otherwise interfere with watermarks. Signal/modulator-carrier chromatography may also separate watermarks from original audio or detect them as glitches. Use of third party media players and other advanced programs render watermarking useless     My book essential 4 generation(640GB/1TB) .

Additionally, comparison of two separately obtained copies of audio using simple, home-grown algorithms can often reveal watermarks. New methods of detection are currently under investigation by both industry and non-industry researchers (WD  My book essential 4 generation( 1.5TB/2TB) .

Metadata

Sometimes, metadata is included in purchased music which records information such as the purchaser's name, account information, or email address. This information is not embedded in the played audio or video data, like a watermark, but is kept separate, but within the file or stream       WD  My book elite( 1TB/1.5TB) .

As an example, metadata is used in media purchased from Apple's iTunes Store for DRM-free as well as DRM-restricted versions of their music or videos. This information is included as MPEG standard metadata.

Laws regarding DRM

Digital rights management systems have received some international legal backing by implementation of the 1996 WIPO Copyright Treaty (WCT)      WD  My book studio(1TB/2TB) .

Article 11 of the Treaty requires nations party to the treaties to enact laws against DRM circumvention.

The WCT has been implemented in most member states of the World Intellectual Property Organization. The American implementation is the Digital Millennium Copyright Act (DMCA)     WD  My book essential 4 generation( 1.5TB/2TB) ,

while in Europe the treaty has been implemented by the 2001 European directive on copyright, which requires member states of the European Union to implement legal protections for technological prevention measures. In 2006, the lower house of the French parliament adopted such legislation as part of the controversial DADVSI law     WD  My book elite(640GB/2TB) ,

but added that protected DRM techniques should be made interoperable, a move which caused widespread controversy in the United States .

Digital Millennium Copyright Act

The Digital Millennium Copyright Act (DMCA) is an amendment to United States copyright law passed unanimously on May 14, 1998, which criminalizes the production and dissemination of technology that allows users to circumvent technical copy-restriction methods       Seagate  expansion portable (320GB/500GB) .

Under the Act, circumvention of a technological measure that effectively controls access to a work is illegal if done with the primary intent of violating the rights of copyright holders. (For a more detailed analysis of the statute, see WIPO Copyright and Performances and Phonograms Treaties Implementation Act      Seagate  expansion portable (750GB/1TB) .)

Reverse engineering of existing systems is expressly permitted under the Act under specific conditions. Under the reverse engineering safe harbor, circumvention necessary to achieve interoperability with other software is specifically authorized. See 17 U.S.C. Sec. 1201(f)   Seagate  expansion (1.5TB/2TB) .

Open-source software to decrypt content scrambled with the Content Scrambling System and other encryption techniques presents an intractable problem with the application of the Act. Much depends on the intent of the actor. If the decryption is done for the purpose of achieving interoperability of open source operating systems with proprietary operating systems     Seagate  Freeagent Desktop (500GB/1TB) ,

the circumvention would be protected by Section 1201(f) the Act. Cf., Universal City Studios, Inc. v. Corley, 273 F.3d 429 (2d Cir. 2001) at notes 5 and 16. However, dissemination of such software for the purpose of violating or encouraging others to violate copyrights has been held illegal. See Universal City Studios, Inc. v. Reimerdes, 111 F. Supp. 2d 346 (S.D.N.Y. 2000)   Seagate  Freeagent Go(250GB/320GB) .

On 22 May 2001, the European Union passed the EU Copyright Directive, an implementation of the 1996 WIPO Copyright Treaty that addressed many of the same issues as the DMCA.

The DMCA has been largely ineffective in protecting DRM systems, as software allowing users to circumvent DRM remains widely available   Seagate  Freeagent Go(500GB/640GB) .

However, those who wish to preserve the DRM systems have attempted to use the Act to restrict the distribution and development of such software, as in the case of DeCSS.

Although the Act contains an exception for research, the exception is subject to vague qualifiers that do little to reassure researchers. Cf., 17 U.S.C. Sec. 1201(g)      Seagate  Freeagent Go(750GB/1TB) .

The DMCA has had an impact oncryptography, because many[who?] fear that cryptanalytic research may violate the DMCA. The arrest of Russian programmer Dmitry Sklyarov in 2001, for alleged infringement of the DMCA, was a highly publicized example of the law's use to prevent or penalize development of anti-DRM measures      Seagate  Freeagent Goflex(250GB/320GB) .

Sklyarov was arrested in the United States after a presentation at DEF CON, and subsequently spent several months in jail. The DMCA has also been cited as chilling to non-criminal inclined users, such as students of cryptanalysis (including, in a well-known instance, Professor Felten and students at Princeton )     Seagate Freeagent Goflex(500GB/640GB) ,

and security consultants such as the Netherlands based Niels Ferguson, who has declined to publish information about vulnerabilities he discovered in an Intel secure-computing scheme because of his concern about being arrested under the DMCA when he travels to the US      Seagate  Freeagent Goflex(750GB/1TB) .

On 25 April 2007 the European Parliament supported the first directive of EU, which aims to harmonize criminal law in the member states. It adopted a first reading report on harmonizing the national measures for fighting copyright abuse. If the European Parliament and the Council approve the legislation, the submitted directive will oblige the member states to consider a crime a violation of international copyright committed with commercial purposes   Seagate  Freeagent Goflex Pro(500GB/750GB) .

The text suggests numerous measures: from fines to imprisonment, depending on the gravity of the offense.

The EP members supported the Commission motion, changing some of the texts. They excluded patent rights from the range of the directive and decided that the sanctions should apply only to offenses with commercial purposes     Seagate  Freeagent Goflex desktop(1TB/2TB) .

Copying for personal, non-commercial purposes was also excluded from the range of the directive.

International issues

In Europe, there are several ongoing dialog activities that are characterized by their consensus-building intention  Seagate  Freeagent go for Mac(320GB/640GB) :

• Workshop on Digital Rights Management of the World Wide Web Consortium (W3C), January 2001.
• Participative preparation of the European Committee for Standardization/Information Society Standardisation System (CEN/ISSS) DRM Report, 2003 (finished)      Samsung  G2 protable (250gb/320GB) .
• DRM Workshops of Directorate-General for Information Society and Media (European Commission) (finished), and the work of the DRM working groups (finished), as well as the work of the High Level Group on DRM (ongoing).
• Consultation process of the European Commission, DG Internal Market, on the Communication COM(2004)261 by the European Commission on "Management of Copyright and Related Rights" (closed)       Samsung  G2 protable (500GB/640GB) .
• The INDICARE project is an ongoing dialogue on consumer acceptability of DRM solutions in Europe. It is an open and neutral platform for exchange of facts and opinions, mainly based on articles by authors from science and practice.
• The AXMEDIS project is a European Commission Integrated Project of the FP6. The main goal of AXMEDIS is automating the content production, copy protection and distribution, reducing the related costs and supporting DRM at both B2B and B2C areas harmonising them          Samsung  S2 protable (160GB/250GB) .
• The Gowers Review of Intellectual Property is the result of a commission by the British Government from Andrew Gowers, undertaken in December 2005 and published in 2006, with recommendations regarding copyright term, exceptions, orphaned works, and copyright enforcement     Samsung  S2 protable (320GB/500GB) .

Controversy

DRM opposition

Many organizations, prominent individuals, and computer scientists are opposed to DRM. Two notable DRM critics are John Walker, as expressed for instance, in his article The Digital Imprimatur Samsung  S1 Mini (120GB/160GB) :

How big brother and big media can put the Internet genie back in the bottle, and Richard Stallman in his article The Right to Readand in other public statements: "DRM is an example of a malicious feature - a feature designed to hurt the user of the software, and therefore, it's something for which there can never be toleration     Samsung  S1 Mini (250GB/320GB) ".

Professor Ross Anderson of Cambridge University heads a British organization which opposes DRM and similar efforts in the UK and elsewhere. Cory Doctorow, a prominent writer and technology blogger, spoke on the Microsoft campus criticizing the technology, the morality, and the marketing of DRM     Samsung  story station (1TB/1.5TB) .

There have been numerous others who see DRM at a more fundamental level. TechMediums.com argues that DRM-free music allows for viral marketing, arguing that independent artists benefit from "free marketing" and can then focus on revenues from higher margin products like merchandise and concert ticket sales       Samsung  Story station (1.5TB/2TB) .

This is similar to some of the ideas in Michael H. Goldhaber's presentation about "The Attention Economy and the Net" at a 1997 conference on the "Economics of Digital Information." (sample quote from the "Advice for the Transition" section of that presentation:  "If you can't figure out how to afford it without charging, you may be doing something wrong        Samsung  story station Esata(1TB/1.5TB) ."

The Electronic Frontier Foundation and similar organizations such as FreeCulture.org also hold positions which are characterized as opposed to DRM.

The Foundation for a Free Information Infrastructure has criticized DRM's impact as a trade barrier from a free market perspectiveSamsung  G3 station (1TB/1.5TB) .

The final version of the GNU General Public License version 3, as released by the Free Software Foundation, has a provision that 'strips' DRM of its legal value, so people can break the DRM on GPL software without breaking laws like the DMCA. Also, in May 2006, the FSF launched a "Defective by Design" campaign against DRM    Maxtor one touch 4 mini (250GB/320GB) .

Creative Commons provides licensing options encouraging the expansion of and building upon creative work without the use of DRM. In addition, the use of a Creative Commons-licensed work on a device which incorporates DRM is a breach of the Baseline Rights asserted by each license        Maxtor  one touch 4 plus (500GB/750GB) .

Bill Gates spoke about DRM at CES in 2006. According to him, DRM is not where it should be, and causes problems for legitimate consumers while trying to distinguish between legitimate and illegitimate users.

According to Steve Jobs, Apple opposes DRM music after a public letter calling its music labels to stop requiring DRM on its iTunes Store        Maxtor  one touch 4 plus (1TB/1.5TB) .

As of January 6, 2009, the iTunes Store is DRM-free for songs. However, Apple considers DRM on video content as a separate issue and has not removed DRM from all of its video catalog.

Defective by Design member protesting DRM on May 25, 2007      Maxtor  black diamond (320GB/500GB) .

As already noted, many DRM opponents consider "digital rights management" to be a misnomer. They argue that DRM manages rights (or access) the same way prison manages freedom and often refer to it as "digital restrictions management". Alternatively, ZDNet Executive Editor David Berlind suggests the term "Content Restriction, Annulment and Protection" or "CRAP" for short     Maxtor cool black(640GB/1TB) .

The Norwegian Consumer rights organization "Forbrukerrådet" complained to Apple Inc. in 2007 about the company's use of DRM in, and in conjunction with, its iPod and iTunes products. Apple was accused of restricting users' access to their music and videos in an unlawful way, and of using EULAswhich conflict with Norwegian consumer legislation      Maxtor  Black diamond (320GB/500GB) .

The complaint was supported by consumers' ombudsmen in Sweden and Denmark, and is currently being reviewed in the EU. Similarly, the United States Federal Trade Commission held hearings in March 2009 to review disclosure of DRM limitations to customers' use of media products    Hitachi  simple touch (250GB/320GB) .

The use of DRM may also be a barrier to future historians, since technologies designed to permit data to be read only on particular machines, or with particular keys, or for certain periods, may well make future data recovery impossible — see Digital Revolution.

DRM opponents argue that the presence of DRM violates existing private property rights and restricts a range of heretofore normal and legal user activities       Hitachi  simple touch (320GB/500GB) .

A DRM component would control a device a user owns (such as a Digital audio player) by restricting how it may act with regards to certain content, overriding some of the user's wishes (for example, preventing the user from burning a copyrighted song to CD as part of a compilation or a review)    Hitachi  life studio (250GB/320GB) .

An example of this effect may be seen in Microsoft's Windows Vista operating system in which content using a Protected Media Path is disabled or degraded depending on the DRM scheme's evaluation of whether the hardware and its use are 'secure'. All forms of DRM depend on the DRM enabled device (e.g., computer, DVD player, TV) imposing restrictions that (at least by intent) cannot be disabled or modified by the user  Hitachi  life studio (320GB/500GB) .

Key issues around digital rights management such as the right to make personal copies, provisions for persons to lend copies to friends, provisions for service discontinuance, hardware agnosticism, software and operating system agnosticism, contracts for public libraries, and customers´ protection against one-side amendments of the contract by the publisher have not been fully addressed      Hitachi life studio platinum (250GB/320GB) .

(see references 80-89) It has also been pointed out that it is entirely unclear whether owners of content with DRM are legally permitted to pass on their property as inheritance to another person.

Tools like FairUse4WM have been created to strip Windows Media of DRM restrictions    Hitachi  life studio platinum (320GB/500GB).

Valve Corporation President Gabe Newell also stated "most DRM strategies are just dumb" because they only decrease the value of a game in the consumer's eyes. Newell's suggests combating piracy by " greater value for customers through service value".

"DRM-Free"

Due to the strong opposition that exists to DRM, many companies and artists have begun advertising their products as "DRM-Free"  Hitachi  life studio desk (500GB/1TB) .

Apple began selling "DRM-Free" music through their iTunes store in April 2007. It was later revealed that the DRM-Free iTunes files were still embedded with each user's account information, a technique called Digital watermarking generally not regarded as DRM. In January 2009, iTunes began marketing all of their songs as "DRM-Free",  however iTunes continues to use DRM on movies, TV shows, ringtones, and audiobooks      Hitachi  life studio plus (320GB/500GB) .

Impossible task

Bruce Schneier has written about the futility of digital copy prevention and says it's an impossible task. He says "What the entertainment industry is trying to do is to use technology to contradict that natural law. They want a practical way to make copying hard enough to save their existing business. But they are doomed to fail    Hitachi  life studio plus (320GB/500GB) ."

He has also described trying to make digital files uncopyable as being like "trying to make water not wet". The creators of StarForce also take this stance, stating that "The purpose of copy protection is not making the game uncrackable - it is impossible."

Both the Association for Computing Machinery and the Institute of Electrical and Electronics Engineers have historically opposed DRM, even going so far as to name AACS as a technology "most likely to fail" in an issue of IEEE Spectrum  Hitachi  X mobile (250GB/320GB) .

Shortcomings

Methods to bypass DRM

There are many methods to bypass DRM control on audio and video content.

One simple method to bypass DRM on audio files is to burn the content to an audio CD and then rip it into DRM-free files  Hitachi  X mobile(320GB/500GB) .

This is only possible when the software that plays these DRM-restricted audio files allows CD-burning. Some software products simplify and automate this burn-rip process by allowing the user to burn music to a CD-RW disc or to a Virtual CD-R drive, then automatically ripping and encoding the music, and automatically repeating this process until all selected music has been converted, rather than forcing the user to do this one CD (72–80 minutes worth of music) at a time    Hitachi External HDD –XL (1TB/2TB) .

Many software programs have been developed that intercept the data stream as it is decrypted out of the DRM-restricted file, and then use this data to construct a DRM-free file. These programs require a decryption key. Programs that do this for DVDs, HD DVDs, and Blu-ray Discs include universal decryption keys in the software itself    (Dell Latitude XT2 Tablet PC Battery)     .

Programs that do this for TiVo ToGo recordings, iTunes audio, and PlaysForSure songs, however, rely on the user's own key — that is, they can only process content that the user has legally acquired under his or her own account.

Another method is to use software to record the signals being sent through the audio or video cards, or to plug analog recording devices into the analog outputs of the media player     (Toshiba Portege 335CT Battery)   .

These techniques utilize the so-called "analog hole" (see below).

Analog hole

All forms of DRM for audio and visual material (excluding interactive materials, e.g. videogames) are subject to the analog hole, namely that in order for a viewer to play the material, the digital signal must be turned into an analog signal containing light and/or sound for the viewer, and so available to be copied as no DRM is capable of controlling content in this form    (Dell Vostro A90 Battery)      .

In other words, a user could play a purchased audio file while using a separate program to record the sound back into the computer into a DRM-free file format.

All DRM to date can therefore be bypassed by recording this signal and digitally storing and distributing it in a non DRM limited form, by anyone who has the technical means of recording the analog stream    (Toshiba Satellite P15  Battery)      .

However the conversion from digital to analog and back is likely to force a loss of quality, particularly when using lossy digital formats. HDCP is an attempt to restrict the analog hole, although it is largely ineffective.

Asus released a soundcard which features a function called "Analog Loopback Transformation" to bypass the restrictions of DRM. This feature allows the user to record DRM-restricted audio via the soundcard's built-in analog I/O connection      (Toshiba Satellite Pro M10 Battery)       .

DRM on general computing platforms

Many of the DRM systems in use are designed to work on general purpose computing hardware, such as desktop PCs apparently because this equipment is felt to be a major contributor to revenue loss from disallowed copying. Large commercial copyright infringers ("pirates") avoid consumer equipment, so losses from such infringers will not be covered by such provisions    (Toshiba Portege 3110 Battery)        .

Such schemes, especially software based ones, can never be wholly secure since the software must include all the information necessary to decrypt the content, such as the decryption keys. An attacker will be able to extract this information, directly decrypt and copy the content, which bypasses the restrictions imposed by a DRM system     (Toshiba Portege R600 Battery)      .

DRM on purpose-built hardware

Many DRM schemes use encrypted media which requires purpose-built hardware to hear or see the content. This appears to ensure that only licensed users (those with the hardware) can access the content. It additionally tries to protect a secret decryption key from the users of the system     (Toshiba Satellite 1900 Battery)        .

While this in principle can work, it is extremely difficult to build the hardware to protect the secret key against a sufficiently determined adversary. Many such systems have failed in the field. Once the secret key is known, building a version of the hardware that performs no checks is often relatively straightforward     (Toshiba Portege R200 Battery)     .

In addition user verification provisions are frequently subject to attack, pirate decryptionbeing among the most frequented ones.

A common real-world example can be found in commercial direct broadcast satellite television systems such as DirecTV and Malaysia's Astro         (SONY VAIO VGN-FZ21m Battery)     .

The company uses tamper-resistant smart cards to store decryption keys so that they are hidden from the user and the satellite receiver. However, the system has been compromised in the past, and DirecTV has been forced to roll out periodic updates and replacements for its smart cards     (SONY VAIO VGN-FZ18m Battery)      .

Watermarks

Watermarks can very typically be removed, although degradation of video or audio can occur.

Mass piracy failure

Mass piracy of hard copies does not necessarily need DRM to be decrypted or removed, as it can be achieved by bit-perfect copying of a legally obtained medium without accessing the decrypted content      (Dell Vostro A90 Battery)      .

Additionally, still-encrypted disk images can be distributed over the Internet and played on legitimately licensed players.

Obsolescence

When standards and formats change, it may be difficult to transfer DRM-restricted content to new media   (Dell Vostro A860 Battery) .

Additionally, any system that requires contact with an authentication server is vulnerable to that server becoming unavailable, as happened  in 2007 when videos purchased from Major League Baseball (mlb.com) prior to 2006 became unplayable due to a change to the servers that validate the licences    (Dell Vostro 2510 Battery)        .

Microsoft Zune - When Microsoft introduced their Zune[84] media player in 2006, it did not support content that uses Microsoft's own PlaysForSure DRM scheme they had previously been selling. TheEFF calls this "a raw deal".

MSN Music - In April 2008, Microsoft sent an email to former customers of the now-defunct MSN Music store: "As of August 31, 2008      (Dell Vostro 1700 Battery)      ,

we will no longer be able to support the retrieval of license keys for the songs you purchased from MSN Music or the authorization of additional computers. You will need to obtain a license key for each of your songs downloaded from MSN Music on any new computer, and you must do so before August 31, 2008   (Dell Vostro 1400 Battery)           .

If you attempt to transfer your songs to additional computers after August 31, 2008, those songs will not successfully play."

However, to avoid a public relations disaster, Microsoft re-issued MSN Music shutdown statement on June 19th and allowed the users to use their licenses until the end of 2011    (HP Pavilion DV7 Battery)

: "After careful consideration, Microsoft has decided to continue to support the authorization of new computers and devices and delivery of new license keys for MSN Music customers through at least the end of 2011, after which we will evaluate how much this functionality is still being used and what steps should be taken next to support our customers     (HP Pavilion DV4 Battery)     .

This means you will continue to be able to listen to your purchased music and transfer your music to new PCs and devices beyond the previously announced August 31, 2008 date."

Terminology

Media corporations have always used the term copy protection, but critics argue that the term tends to sway the public into identifying with the publishers, who favor restriction technologies, rather than with the users         (Dell Studio XPS 1640 Battery) .

Copy prevention and copy control may be more neutral terms. "Copy protection" is a misnomer for some systems, because any number of copies can be made from an original and all of these copies will work, but only in one computer, or only with one dongle, or only with another device that cannot be easily copied   (Dell Studio XPS 1340 Battery)    .

The term is also often related to and/or confused with the concept of digital rights management. Digital rights management is a more general term because it includes all sorts of management of works, including copy restrictions. Copy protection may include measures that are not digital   (Dell Vostro 1710 Battery)    .

A more appropriate term is "technological protection measures" (TPMs) , which is often defined as the use of technological tools in order to restrict the use and/or access to a work.

Business rationale

Copy protection is most commonly found on videotapes, DVDs, computer software discs, video game discs and cartridges, and some audio CDs   (Sony VGP-BPS13 battery)  .

Many media formats are easy to copy using a machine, allowing consumers to distribute copies to their friends, a practice known as "casual copying".

Companies publish works under copy protection because they believe that the cost of implementing the copy protection will be less than the revenue produced by consumers who buy the product instead of acquiring it through casually copying       (Sony VGP-BPS13/B battery)      .

Opponents of copy protection argue that people who obtain free copies only use what they can get for free, and would not purchase their own copy if they were unable to obtain a free copy. Some even argue that it increases profit; people who receive a free copy of a music CD may then go and buy more of that band's music, which they would not have done otherwise (Sony VGP-BPS13/S battery) .

Some publishers have avoided copy-protecting their products, on the theory that the resulting inconvenience to their users outweighs any benefit of frustrating "casual copying".

From the perspective of the end user, copy protection is always a cost   (Sony VGP-BPS13A/B battery)   .

DRM and license managers sometimes fail, are inconvenient to use, and do not afford the user all of the legal use of the product they have purchased.

The term copy protection refers to the technology used to attempt to frustrate copying, and not to the legal remedies available to publishers or authors whose copyrights are violated    (Sony VGP-BPS13B/B battery)  .

Software usage models evolve beyond node locking to floating licenses (where up to N licenses can be concurrently used across an enterprise), grid computing (where multiple computers function as one unit and so use a common license) and electronic licensing (where features can be purchased and activated online)      (Sony VGP-BPS13B/B battery)     .

The term license management refers to broad platforms which enable the specification, enforcement and tracking of software licenses. To safeguard copy protection and license management technologies themselves against tampering and hacking, software anti-tamper methods are used      (Sony VGP-BPL9 battery)      .

Technical challenges

From a technical standpoint, it would seem theoretically impossible to completely prevent users from making copies of the media they purchase, as long as a "writer" is available that can write to blank media. The basic technical fact is that all types of media require a "player"—a CD player, DVD player, videotape player, computer, or video game console  (Sony VGP-BPL11 battery)    .

The player has to be able to read the media in order to display it to a human. In turn, then, logically, a player could be built that first reads the media, and then writes out an exact copy of what was read, to the same type of media, or perhaps to some other format, such as a file on a hard disk      (Sony VGP-BPL15 battery)      .

If to another disk, then the result is an exact duplicate of the copy protected disc   .

At a minimum, digital copy protection of non-interactive works is subject to the analog hole: regardless of any digital restrictions, if music can be heard by the human ear, it can also be recorded (at the very least, with a microphone and tape recorder)     (Dell Inspiron E1505 battery)      ;

if a film can be viewed by the human eye, it can also be recorded (at the very least, with a video camera and recorder). In practice, almost-perfect copies can typically be made by tapping into the analog output of a player (e.g. the speaker output or headphone jacks) and, once redigitized into an unprotected form, duplicated indefinitely     (Dell Latitude E6400 battery)       .

Copyingtext-based content in this way is more tedious, but the same principle applies: if it can be printed or displayed, it can also be scanned and OCRed. With basic software and some patience, these techniques can be applied by a typical computer-literate user (HP Pavilion dv6000 Battery)     .

Since these basic technical facts exist, it follows that a determined individual will definitely succeed in copying any media, given enough time and resources. Media publishers understand this; copy protection is not intended to stop professional operations involved in the unauthorized mass duplication of media, but rather to stop "casual copying"   (Sony Vaio VGN-FZ31S battery)     .

Copying of information goods which are downloaded (rather than being mass-duplicated as with physical media) can be inexpensively customized for each download, and thus restricted more effectively. They can be encrypted in a fashion which is unique for each user's computer, and the decryption system can be made tamper-resistant (see also traitor tracing)    (Sony VGN-FZ31S battery)    .

Copy protection for computer software

Copy protection for early home computer software, especially for games, started a long cat-and-mouse struggle between publishers and crackers      (Hp pavilion dv6000 battery)   .

These were (and are) programmers who as a hobby would defeat copy protection on software, add their alias to the title screen, and then distribute the cracked product to the network of warez BBSes or Internet sites that specialized in distributing unauthorized copies of software    (SONY VGN-FZ38M Battery)        .

Software copy protection schemes for early computers such as the Apple II and Commodore 64 computers were extremely varied and creative because most of the floppy disk reading and writing was controlled by software, not by hardware; for the IBM-PC these were known as 'booters'      (SONY VGN-FZ31z Battery)       .

The first copy protection was for cassette tapes and consisted of a loader at the beginning of the tape, which read a specially formatted section which followed.

The first protection of floppy disks consisted of changing the address marks, bit slip marks, data marks, or end of data marks for each sector       (Sony VGN-FZ31Z Battery)       .

For example, Apple’s standard sector markings were:

D5 AA 96 for the address mark. That was followed by track, sector, and checksum.

DE AA EB concluded the address header with what are known as bit slip marks  (SONY VGN-FZ31E Battery)        .

D5 AA AD was used for the data mark and the end of data mark was another DE AA EB.

Changing any of these marks required changing the software which read the floppy disk, but produced a disk that could not be copied. Some systems used complicated systems that changed the marks by track or even within a track        (SONY  VGN-FZ31J Battery)      .

By 1980 the first nibble copier, Locksmith, was introduced. These copiers reproduced copy protected floppy disks an entire track at a time, ignoring how the sectors were marked. This was harder to do than it sounds, because Apple disks did not use the index hole to mark the start of a track      (SONY VGN-FZ31M Battery)    .

Tracks could start anywhere. Nevertheless, Locksmith copied Apple II disks by taking advantage of the sync fields between sectors, which consisted of a long string of FF (hex) bytes between each sector. It found the longest string of FFs, which occurred between the last and first sectors on each track, and began writing the track in the middle of that     (SONY VGN-FZ31B Battery)     .

Ironically, Locksmith would not copy itself. The first Locksmith measured the distance between sector 1 of each track. Copy protection engineers quickly figured out what Locksmith was doing and began to use the same technique to defeat it. Locksmith countered by introducing the ability to reproduce track alignment and prevented itself from being copied by embedding a special sequence of nibbles, that if found, would stop the copy process    (SONY VGP-BPS13 Battery)    .

Henry Roberts (CTO of Nalpeiron), a graduate student in computer science at the University of South Carolina reverse engineered Locksmith, found the sequence and distributed the information to some of the 7 or 8 people producing copy protection at the time.

For some time, Locksmith continued to defeat virtually all of the copy protection systems in existence  (Dell Inspiron 1320 Battery) .

The next advance came from Henry Roberts thesis on software copy protection, which devised a way of replacing Apple’s sync field of FFs, with random appearing patterns of bytes. Because the graduate student had frequent copy protection discussions with Apple’s copy protection engineer, Apple developed a copy protection system which made use of this technique (Dell Inspiron 1320n Battery)   .

Henry Roberts then wrote a competitive program to Locksmith, Back It UP. He devised several methods for defeating that, and ultimately a method was devised for reading self sync fields directly, regardless of what nibbles they contained.

The back and forth struggle between copy protection engineers and nibble copiers continued until the Apple II became obsolete and was replaced by the IBM PC and its clones   (Dell Inspiron 1464 Battery)    .

Floppy disks were replaced by CDs as the preferred method of distribution, and companies like Macrovision and Sony providing copy protection schemes that work by writing data to places on the CD-ROM where a CD-R drive cannot normally write. Such a scheme has been used for the PlayStation and cannot be circumvented easily without the use of a modchip      (Dell Inspiron 1564 Battery)    .

For software publishers, a less expensive method of copy protection is to write the software so that it requires some evidence from the user that they have actually purchased the software, usually by asking a question that only a user with a software manual could answer (for example, "What is the 4th word on the 6th line of page 37?")     (Dell Inspiron 1764 Battery)     .

This approach can be defeated by users who have the patience to copy the manual with a photocopier, and it also suffers from the fact that once crackers circumvent the copy protection on a piece of software, the resulting cracked product is more convenient than the original software, creating a disincentive to buying an original     (Dell Studio 1450 Battery)        .

As a result, user-interactive copy protection of this kind has mostly disappeared.

Other software copy protection techniques include:

• A dongle, a piece of hardware containing an electronic serial number that must be plugged into the computer to run the software. This adds extra cost for the software publisher, so dongles are uncommon for games and are found mostly in expensive high-end software packages    (Dell Studio 1457 Battery)    .
• Rainbow (SafeNet), HASP (Aladdin Knowledge Systems), iLok (Copy Protection) and Matrix Software License Protection System SecuTech's UniKey are popular dongle protection schemes utilizing a USB dongle. For the production of even more restrictive software, a dongle product that supports code porting mechanism is one choice available to software developers (Dell Latitude D610 Battery)    .
• Bus encryption and encrypted code for use in Secure cryptoprocessors. This prevents copying and tampering of programs used in high security environments such as ATMs. This hardware solution is based on the fact that unlike music, video, and text that must eventually be revealed to users to be heard, viewed, or read, program instructions are needed only by the cryptoprocessor that decrypts and executes them   (Toshiba NB100 Battery)    .
• A registration key, a series of letters and numbers that is asked for when running the program. Many computer games use registration keys. The software will refuse to run if the registration key is not typed in correctly, and multiplayer games will refuse to run if another user is online who has used the same registration key       (Toshiba Satellite M65 battery) .
• Name & Serial, a name and serial number that is given to the user at the time the software is purchased, and is required to install it.
• Keyfile, which requires the user to have a keyfile in the same directory as the program is installed to run it   (Toshiba Satellite M60 battery)      .
• A phone activation code, which requires the user to call a number and register the product to receive a computer-specific serial number    (Dell Latitude D830 Battery)   .
• Internet product activation, which requires the user to connect to the Internet, or exchange encrypted files with the vendor, so the software can "call home" and notify the manufacturer who has installed the software and where, and prevent other users from installing the software if they attempt to use the same serial number   (Dell Latitude D620 Battery)    .
• Microsoft's Windows Genuine Advantage system is a far-reaching example of this.
• Protection by code morphing or code obfuscation. The Code Morphing is multilevel technology containing hundreds of unique code transformation patterns     (Dell Studio 1735 Battery)     .
• In addition this technology includes the special layer that transforms some commands into Virtual Machine commands (like P-Code). Code Obfuscation turns binary code into an undecipherable mess that is not similar to normal compiled code, and completely hides execution logic of the protected code    (Dell Inspiron Mini 10 Battery)   .

Copy protection methods usually tie the installed software to a specific machine by involving some unique feature of the machine. Some machines have a serial number in ROM, while others do not, and so some other metric, such as the date and time (to the second) of initialization of the hard disk can be used        (Sony VGN-FW11S Battery)      .

On machines with Ethernet cards, the MAC address, which is unique and factory-assigned, is a popular surrogate for a machine serial number; however, this address is programmable on modern cards. With the rise of virtualization the practice of locking has to add to these simple hardware parameters to still prevent copying    (Sony VGN-FW11M Battery)   .

These schemes have all been criticized for causing problems for validly licensed users who upgrade to a new machine, or have to reinstall the software after reinitializing their hard disk. Some Internetproduct activation products allow replacement copies to be issued to registered users or multiple copies to the same license    (Dell Studio 1555 battery)     .

Like all software, copy-protection software sometimes contains bugs, whose effect may be to deny access to validly licensed users. Most copy protection schemes are easy to crack, and the resulting cracked software is then more valuable than the non-cracked version, because users can make additional copies   (Dell Latitude E5400 Battery)   .

In his 1976 Open Letter to Hobbyists, Bill Gates complained that "most of you steal your software." However, Gates initially rejected copy protection and said "It just gets in the way."

There is also the tool of software blacklisting that is used to enhance certain copy protection schemes    (Dell Latitude E4200 Battery)     .

Copy protection specific to old games

During the 1980s and 1990s, computer games sold on audio cassette and floppy disks were sometimes protected with a user-interactive method that demanded the user to have the original package or a part of it, usually the manual    (Dell Vostro A840 Battery)    .

Copy protection was activated not at installation but every time the game was executed.

Sometimes the copy protection code was needed not at launch, but at a later point in the game. This helped the gamer to experience the game (e.g. as a demonstration) and perhaps could convince him to buy it by the time the copy protection point was reached  (Dell Inspiron 300M Battery)       .

Several imaginative and creative methods have been employed, in order to be both fun and hard to copy. These include:

• The most common method ("What is the 13th word on the 7th line of page 22?") was often used at the beginning of each game session, but as it proved to be troublesome and tiring for the players, it declined in popularity (for example, X-COM: UFO Defense used it too, but was later removed by the official v1.4 patch)    (Dell Studio 1737 battery)    .
• A variant of this technique involved matching a picture provided by the game to one in the manual and providing an answer pertaining to the picture (Ski or Die and 4D Boxing used this technique). Buzz Aldrin's Race Into Space (in the floppy version but not the CD version) incorporated a copy protection scheme that required the user to input an astronaut's total duration in space (available in the manual) before the launch of certain missions  (Dell Inspiron E1505 battery)   .
• If the answer was incorrect, the mission would suffer a catastrophic failure.
• Manuals containing information and hints vital to the completion of the game, like answers to riddles (Conquests of Camelot, King's Quest 6), recipes of spells (King's Quest 3), keys to deciphering non-Latin writing systems (Ultima series, see also Ultima writing systems), maze guides (Manhunter)    (Dell Latitude E6400 battery)    ,
• dialogue spoken by other characters in the game (Wasteland, Dragon Wars), excerpts of the storyline (most Advanced Dungeons and Dragons games and Wing Commander I), or a radio frequency to use to communicate with a character to further a game (Metal Gear Solid)     (Dell RM791 battery)    .
• Some sort of code with symbols, not existing on the keyboard or the ASCII code. This code was arranged in a grid, and had to be entered via a virtual keyboard at the request "What is the code at line 3 row 2?". These tables were printed on dark paper (Maniac Mansion, Uplink)       (Dell XPS M1530 battery)     ,
• or were visible only through a red transparent layer (Indiana Jones and the Last Crusade), making the paper very difficult to photocopy. Another variant of this method—most famously used on the ZX Spectrum version of Jet Set Willy—was a card with color sequences at each grid reference that had to be entered before starting the game    (Dell XPS M2010 battery)  .
• This also prevented photocopying.
• The Secret of Monkey Island offered one of the most imaginative protection keys: a rotating wheel with halves of pirate's faces. The game showed a face composed of two different parts and asked when this pirate was hanged on a certain island   (Dell Vostro 1000 battery)       .
• The player then had to match the faces on the wheel, and enter the year number that appeared on the island-respective hole. Its sequel had the same concept, but with magic potion ingredients. Other games that employed the code wheel system include games from Accolade like Star Control    (Acer Aspire One battery) .
• Zork games such as Beyond Zork and Zork Zero came with "feelies" which contained information vital to the completion of the game. For example, the parchment found from Zork Zero contained clues vital to solving the final puzzle. However, whenever the player attempts to read the parchment, they are referred to the game package    (Toshiba Satellite P10 Battery)     .
• The in-game help function alluded to this form of control with the response "Good luck, Blackbeard" to queries that were unsolvable without the original game materials.
• The lenslok system used a plastic prismatic device, shipped with the game, which was used to descramble a code displayed on screen        (SONY VGN-FZ210CE Battery)      .

While not strictly a software protection, some game companies offered "value-added" goodies with the package, like funny manuals, posters, comics, storybooks or fictional documentation concerning the game (e.g. the Grail Diary for Indiana Jones or a police cadet notebook with Police Quest or the Hero's manual of Quest for Glory or a copy of the National Inquisitor newspaper in Zak McKracken) in order to entice gamers to buy the package      (Dell Precision M70 Battery)    .

This trend is re-emerging in modern gaming as an incentive to both buy games and discourage their resale; some games like Forza Motorsport 3 andDragon Age: Origins provide bonus in-game material that will only be given if one buys the game new     (Toshiba Satellite L305 Battery)     .

Copy protection methods of recent video game console systems

When Sega's Dreamcast was released September 9, 1999, it came with a newer disc format, called the GD-ROM. Using a modified CD player, one could access the game functionality       (Toshiba Satellite T4900 Battery)    .

Using a special swap method could allow reading a GD-ROM game through a CD-ROM just using common MIL-CD (standard CD Boot loading, commonly found on Windows Installation Discs, Linux Live CDs, and others). Dreamcasts sold after October 2000 contain a newer firmware update, not allowing MIL-CD boot      (Toshiba PA3399U-2BRS battery)     .

The Xbox has a specific function: Non-booting or non-reading from CDs and DVD-Rs as a method of game copy protection. Also, the Xbox is said to use a different DVD file system (instead of UDF). It has been theorized that the discs have a second partition that is read from the outside in     (Toshiba Satellite A200 Battery)

(opposite current standards thus making the second partition unreadable in PC DVD drives) which give the tracks the appearance that the disc was spun backwards during manufacture. The Xbox 360 copy protection functions by requesting the DVD drive compute the angular distance between specific data sectors on the disc     (Toshiba Satellite 1200 Battery)        .

A duplicated DVD will return different values than a pressed original would.

The PlayStation 2 has a map file that contains all of the exact positions and file size info of the CD in it. It is stored at a position that is beyond the file limit. The game directly calls the position at where the map file is supposed to be       (Toshiba Satellite M300 Battery) .

This means that if the file is moved inside the limit, it's useless since the game is looking outside the limit for it. And it will not work outside of the limit, thus making any copied disc unusable without a mod chip or the use of FMCB: free memory card boot. FMCB uses your memory card to trick the built-in DVD video software into booting your copied games   (WD External HDD ---passport essential (500GB/640GB))   .

Before a copied game can be played, it must have been patched with a free application.

Nintendo's Wii and Nintendo GameCube have their own specialty format for copy protection. It is based on DVD/miniDVD (Game Cube) technology; each disc contains some deliberately placed defects      (WD External HDD passport essential (250GB/320GB) .

The exact positions of these defects, which differ for each produced disc, is encoded encrypted in the BCA of each disc. The BCA is readable on most standard DVD-ROM Drives, but consumer burners can reproduce neither the BCA nor the defects. As an additional obfuscation mechanism, the on-disc sector format is a little bit different from normal DVDs     (WD External HDD ---passport essential SE (750GB/1TB) .

Nevertheless, it can be read using some consumer DVD-ROM drives with a firmware modification or "debug mode".

The PSP, except the PSP Go, uses the Universal Media Disc, a media format similar to a MiniDisc. It holds about 1.2 GB. Although it cannot be copied, one can make an ISO image (a file version of the UMD) on a memory card and play it on custom firmware, which can be installed on the PSP        (WD External HDD ---passport elite(250GB/320GB) .

The PlayStation 3 uses Blu-ray BD-ROM discs. In addition to any protection provided by the console itself, the BD-ROM format's specification allows for a ROM-Mark which cannot be duplicated by consumer-level recorders. The BD-ROM format, in addition, has a notably large file size in the neighborhood of 40-50 gigabytes per game, making it unwieldy for online file-sharing, a major method of video game copying        (WD External HDD ---passport elite(500GB/640GB) .

Proposed General Purpose Copy Protection Methods

There is another protection method that is not out yet, US Patent Office for Application Number 11678137. Each and every copy of a protected program gets its own internal intelligence, interpretable only by itself, which includes time of program creation, etc., etc. (WD External HDD ---passport studio for Mac(320GB/500GB) .

Each copy of the game or program must be compiled or otherwise created at the time of purchase. Also, the maker must keep track of a subset of each and every instance of the newly created specialty software in case the user emails in for new keys, say for a reinstall. Perhaps even the purchasers name would be encoded and included as part of the intelligence (WD External HDD ---passport studio for Mac(500GB/640GB) .

The number of permissible occurrences of requests for new key codes, say, 5 times, can be controlled by the program maker. If someone cracks the code for that particular copy of the program, still, it will work only for that copy, and only in the time frame that the internal intelligence says it can be installed     (WD External HDD ---Elements series(250GB/320GB) .

Copy protection for videotape

Companies such as Macrovision and Dwight Cavendish provided schemes to videotape publishers making copies unusable if they were created with a normal VCR. All major videotape duplicators licensed Macrovision or similar technologies to copy protect video cassettes for their clients or themselves       (WD External HDD ---Elements SE(500GB/640GB) .

Starting in 1985 with the video release of "The Cotton Club", Macrovision has licensed to publishers a technology that exploits the automatic gain control feature of VCRs by adding pulses to the vertical blanking sync signal. These pulses do not affect the image a consumer sees on his TV, but do confuse the recording-level circuitry of consumer VCRs    (WD External HDD ---Elements SE(750GB/1TB) .

This technology, which is aided by U.S. legislation mandating the presence of automatic gain-control circuitry in VCRs, is said to "plug the analog hole" and make VCR-to-VCR copies impossible, although an inexpensive circuit is widely available that will defeat the protection by removing the pulses      (WD External HDD --- Elements desktop(500GB/640GB) .

Macrovision has patented methods of defeating copy prevention, giving it a more straightforward basis to shut down manufacture of any device that descrambles it than often exists in the DRM world.

Copy protection for audio CDs

By 2000, Napster had become a popular mainstream hobby, and several music publishers responded by starting to sell some CDs with various copy protection schemes    (WD External HDD --- Elements desktop(750GB/1TB) .

Most of these are playback restrictions that aim to make the CD unusable in computers with CD-ROM drives, leaving only dedicated audio CD players for playback. This does not, however, prevent such a CD from being copied via analogue connections or by ripping the CD under operating systems such as Linux  (WD External HDD --- Elements desktop(1.5 TB/2TB)

(which is effective since copy-protection software is generally written for Microsoft Windows), which has led critics to question the usefulness of such schemes.

CD copy protection is achieved by assuming certain feature levels in the drives  (WD External HDD ---passport essential SE (750GB/1TB)--USB 3.0)   :

The CD Digital Audio is the oldest CD standard and forms the basic feature set beyond which dedicated audio players need no knowledge. CD-ROM drives additionally need to support mixed mode CDs (combined audio and data tracks) and multi-session CDs (multiple data recordings each superseding and incorporating data of the previous session)  (WD External HDD ---passport essential (500GB/640GB) .

The play preventions in use intentionally deviate from the standards and intentionally include malformed multisession data or similar with the purpose of confusing the CD-ROM drives to prevent correct function    (WD External HDD ---passport for Mac(320GB/500GB) .

Simple dedicated audio CD players would not be affected by the malformed data since these are for features they do not support — for example, an audio player will not even look for a second session containing the copy protection data.

In practice, results vary wildly      (WD External HDD ---passport for Mac(640GB/1TB) .

CD-ROM drives may be able to correct the malformed data and still play them to an extent that depends on the make and version of the drive. On the other hand, some audio players may be built around drives with more than the basic intelligence required for audio playback       (WD External HDD ---My book essential 4 generation(640GB/1TB) .

Some car radios with CD playback, portable CD players, CD players with additional support for data CDs containing MP3 files, and DVD players have had problems with these CDs.

The deviation from the Red Book standard that defines audio CDs required the publishers of these copy-protected CDs to refrain from using the official CDDA logo on the discs or the cases   (WD External HDD ---My book essential 4 generation( 1.5TB/2TB) .

The logo is a trademark owned by Philips and Sony and licensed to identify compliant audio discs only. To prevent dissatisfied customers from returning CDs which were misrepresented as compliant audio CDs, such CDs also started to carry prominent notices on their covers      WD External HDD ---My book elite( 1TB/1.5TB) .

In general the audio can always be extracted by applying the principle of the analog hole. Additionally, such programs as IsoBuster may be capable of producing hidden audio files.

Examples of CD copy protection schemes are Cactus Data Shield, Copy Control, and Data Position Measurement      WD External HDD ---My book studio(1TB/2TB) .

Copy protection in recent digital media

More recently, publishers of music and films in digital form have turned to encryption to make copying more difficult. CSS, which is used on DVDs, is a famous example of this. It is a form of copy protection that uses 40-bit encryption    WD External HDD ---My book essential 4 generation( 1.5TB/2TB) .

Copies will not be playable since they will be missing the key, which is not writable on DVD-R or DVD-RW discs. With this technique, the work is encrypted using a key only included in the firmware of "authorized" players, which allow only "legitimate" uses of the work (usually restricted forms of playback, but no conversion or modification)    WD External HDD ---My book elite(640GB/2TB) .

The controversial Digital Millennium Copyright Act provides a legal protection for this in the US, that would make it illegal to distribute "unauthorized" players—which was supposed to eliminate the possibility of building a DVD copier    Seagate External HDD ---expansion portable (320GB/500GB) .

However, encryption schemes designed for mass-market standardized media such as DVD suffer from the fundamental weakness that once implemented, they can never be changed without breaking the standard. Since consumers are highly unlikely to buy new hardware for the sole purpose of preserving copy protection      Seagate External HDD ---expansion portable (750GB/1TB) ,

manufacturers have been prevented from enhancing their DRM technology until recently, with the release of next-generation media such as HD DVD and Blu-ray Disc. This period represents more than enough time for the encryption scheme to be defeated by determined attackers      Seagate External HDD ---expansion (1.5TB/2TB) .

For example, the CSS encryption system used on DVD Video was broken within three years of its market release in November 1996 (see DeCSS), but has not been changed since, because doing so would immediately render all DVD players sold prior to the change incapable of reading new DVDs        Seagate External HDD ---Freeagent Desktop (500GB/1TB) —

this would not only provoke a furious backlash amongst consumers, but massively restrict the market that the new DVDs could be sold to. More recent DVDs have attempted to augment CSS with additional protection schemes      Seagate External HDD ---Freeagent Desk (1.5TB/2TB) .

Most modern schemes likeARccOS Protection use tricks of the DVD format in an attempt to trip up copying programs, though it is noted that any scheme must stay within the bounds of the DVD Video format, limiting the possible avenues of protection—and making it easier for hackers to learn the innards of the scheme and find ways around it      Seagate External HDD ---Freeagent Go(250GB/320GB) .

The newest generations of optical disc media, HD DVD and Blu-ray Disc, attempt to address this issue. Both formats employ the Advanced Access Content System, which provides for several hundred different decryption keys (for the varying models of players to hit the market), each of which can be invalidated ("revoked") should one of the keys be compromised    Seagate External HDD ---Freeagent Go(500GB/640GB) .

Revoked keys simply will not appear on future discs, rendering the compromised players useless for future titles unless they are updated to fix the issue. For this reason, all HD-DVD players and some Blu-ray players include an ethernetport, to give them the ability to download DRM updates      Seagate External HDD ---Freeagent Go(750GB/1TB) .

Blu-ray Disc goes one step further with a separate technique called BD+, a virtual machine that can execute code included on discs to verify, authorize, revoke, and update players as the need arises. Since the protection program is on the disc rather than the player, this allows for updating protection programs within BD's working life by simply having newer programs included on newer discs  Seagate External HDD ---Freeagent Goflex(250GB/320GB) .

Notable copy protection payloads

Over time, software publishers (especially in the case of videogames) became creative about crippling the software in case it was illegally copied. These games would initially show that the copy was successful, but eventually render themselves unplayable via subtle methods        Seagate External HDD ---Freeagent Goflex(500GB/640GB) .

• Superior Soccer had no outward signs of copy protection, but if it decided it was illegally copied, it would make the soccer ball in the game invisible, thus making it impossible to play the game      Seagate External HDD ---Freeagent Goflex(750GB/1TB) .

• While the copy protection in Zak McKracken and the Alien Mindbenders wasn't hidden as such, the repercussions of missing the codes was unusual: the player would end up in jail (permanently), and the police officer would give a lengthy and condescending speech about software copying    Seagate External HDD ---Freeagent Goflex Pro(500GB/750GB) .

• In case of copied versions of Settlers 3, the iron smelters - who are essential to create weapons - would only produce pig irons, making the players inevitably lose weapons because of the lack ofarmour .
• Bohemia Interactive Studio developed a unique and very subtle protection system for its game Operation Flashpoint: Cold War Crisis Seagate External HDD ---Freeagent Goflex desktop(1TB/2TB) .

Dubbed FADE, if it detects an unauthorized copy, it does not inform the player immediately but instead progressively corrupts aspects of the game (such as reducing the weapon accuracy to 0) to the point that it eventually becomes unplayable. The message "Original discs don't FADE" will eventually appear if the game is detected as being an unauthorized copy  Seagate External HDD ---Freeagent go for Mac(320GB/640GB) .

FADE is also used in ArmA II.

• More recently, Batman: Arkham Asylum implemented a copy protection system where the game disables Batman's glide system and various other features, rendering the players to be unable to continue beyond a certain point      Samsung External HDD --G2 protable (250gb/320GB) .

• The PC version of Grand Theft Auto IV has a copy protection that swings the camera as though the player was drunk. If the player entered a vehicle it will automatically throttle, making it difficult to steer. It also damages the vehicle, making it vulnerable to collisions and bullets    Samsung External HDD --G2 protable (500GB/640GB) .

• Earthbound has an interesting anti-copying system. Unauthorized copies of the game will trigger a checksum that makes random encounters appear much more often than in an authorized copy, and if the player progresses through the game without giving up, the game will freeze and delete all the save files right before the final boss battle   Samsung External HDD --S2 protable (160GB/250GB) .

• In an unauthorized version of the PC edition of Mass Effect, the game save mechanism would not work and the in-game galactic map would cause the game to crash. As the galactic map is needed to travel to different sections of the game, the player would be stuck in the first section of the game      Samsung External HDD --S2 protable (320GB/500GB) .

• If an unauthorized version of The Sims 2 was used, the Build Mode would not work properly. Walls would not be able to be built on the player's property, which prevents the player from building any custom houses. Some furniture and clothing selections would not be available too      Samsung External HDD --S1 Mini (120GB/160GB) .

Data masking is the process of obscuring (masking) specific data elements within data stores. It ensures that sensitive data is replaced with realistic but not real data. The goal is that sensitive customer information is not available outside of the authorized environment      Samsung External HDD --S1 Mini (250GB/320GB) .

Data masking is typically done while provisioning non-production environments so that copies created to support test and development processes are not exposing sensitive information and thus avoiding risks of leaking. Masking algorithms are designed to be repeatable so referential integrity is maintained      Samsung External HDD --story station (1TB/1.5TB) .

Common business applications require constant patch and upgrade cycles and require that 6-8 copies of the application and data be made for testing. While organizations typically have strict controls on production systems, data security in non-production instances is often left up to trusting the employee, with potentially disastrous results      Samsung External HDD --Story station (1.5TB/2TB) .

Creating test and development copies in an automated process reduces the exposure of sensitive data. Database layout often changes, it is useful to maintain a list of sensitive columns in a without rewriting application code. Data masking is an effective strategy in reducing the risk of data exposure from inside and outside of an organization and should be considered a best practice for curing non-production databases      Samsung External HDD ---story station Esata(1TB/1.5TB) .

Requirements

Effective data masking requires data to be altered in a way that the actual values cannot be determined or reengineered, functional appearance is maintained, so effective testing is possible. Data can be encrypted and decrypted, relational integrity is maintained, security polices can be established and separation of duties between security and administration established    Samsung External HDD --G3 station (1TB/1.5TB) .

Common methods of data masking includes: encryption/decryption, shuffling, masking (i.e. numbers letters), substitution (i.e. All female names = Julie), nulling (####) or shuffling (zip code12345 = 53412).

Data Masking Techniques

Substitution

The Substitution technique replaces the existing data with random values from a pre-prepared dataset  Maxtor External HDD --one touch 4 mini (250GB/320GB) .

Shuffling

The Shuffling technique uses the existing data as its own substitution dataset and moves the values between rows in such a way that the no values are present in their original rows      Maxtor External HDD --one touch 4 plus (500GB/750GB) .

Number and Date Variance

The Number and Date Variance technique varies the existing values in a specified range in order to obfuscate them. For example, birth date values could be changed within a range of +/- 60 days    Maxtor External HDD --one touch 4 plus (1TB/1.5TB) .

Encryption

The Encryption technique algorythmically scrambles the data. This usually does not leave the data looking realistic and can sometimes make the data larger    Maxtor External HDD --black diamond (320GB/500GB) .

Nulling Out Or Deletion

The Nulling Out technique simply removes the sensitive data by deleting it.

Masking Out

The Masking Out technique sanitizes the data by replacing certain specified characters with mask characters. For example, a credit card number might be masked as 4929 1344 XXXX XXXX      Maxtor External HDD --cool black(640GB/1TB) .

Row-Internal Synchronization

If a row in a database table contains denormalized data derived from other columns in that row and those columns are masked then the denormalized data row will need to be rebuilt. This technique is called Row-Internal Synchronization      Maxtor External HDD --Black diamond (320GB/500GB) .

Table-Internal Synchronization

If a database table contains multiple rows containing identical columns and those columns are masked then the denormalized data rows will need to be set to the same value. This technique is called Table-Internal Synchronization  Hitachi External HDD --simple touch (250GB/320GB) .

Table-To-Table Synchronization

If two tables contain the columns with the same denormalized data values and those columns are masked in one table then the second table will need to be updated with the changes. This technique is called Table-To-Table Synchronization    Hitachi External HDD --simple touch (320GB/500GB) .

This residue may result from data being left intact by a nominalfile deletion operation, by reformatting of storage media that does not remove data previously written to the media, or through physical properties of the storage medium that allow previously written data to be recovered       (Dell Studio XPS 1640 Battery)     .

Data remanence may make inadvertent disclosure of sensitive information possible, should the storage media be released into an uncontrolled environment (e.g., thrown in the trash, or given to a third party).

Various techniques have been developed to counter data remanence      (Dell Studio XPS 1340 Battery)   .

These techniques are classified as clearing, purging/sanitizing or destruction. Specific methods include  overwriting ,  degaussing, encryption, and physical destruction.

Effective application of countermeasures can be complicated by several factors        (Dell Vostro 1710 Battery)     ,

including media that are inaccessible, media that cannot effectively be erased, advanced storage systems that maintain histories of data throughout the data's life cycle, and persistence of data in memory that is typically considered volatile.

Several standards exist for the secure removal of data and the elimination of data remanence       (Sony VGP-BPS13 battery)     .

Causes

Many operating systems, file managers, and other software provide a facility where a file is not immediately deleted when the user requests that action. Instead, the file is moved to a holding area, to allow the user to easily revert a mistake    (Sony VGP-BPS13/B battery) .

Similarly, many software products automatically create backup copies of files that are being edited, to allow the user to restore the original version, or to recover from a possible crash (autosave feature).

Even when an explicit deleted file retention facility is not provided or when the user does not use it    (Sony VGP-BPS13/S battery) ,

operating systems do not actually remove the contents of a file when it is deleted. Instead, they simply remove the file's entry from the file system directory, because this requires less work and is therefore faster. The contents of the file—the actual data—remain on the storage medium    (Sony VGP-BPS13A/B battery)      .

The data will remain there until the operating system reuses the space for new data. In some systems, enough filesystem metadata are also left behind to enable easy undeletion by commonly available utility software. Even when undelete has become impossible, the data, until it has been overwritten, can be read by software that reads disk sectors directly       (Sony VGP-BPS13B/B battery)   .

Computer forensics often employs such software.

Likewise, reformatting, repartitioning or reimaging a system is not always guaranteed to write to every area of the disk, though all will cause the disk to appear empty or, in the case of reimaging, empty except for the files present in the image, to most software (Sony VGP-BPS13B/B battery)     .

Finally, even when the storage medium is overwritten, physical properties of the medium may make it possible to recover the previous contents. In most cases however, this recovery is not possible by just reading from the storage device in the usual way, but requires using laboratory techniques such as disassembling the device and directly accessing/reading from its components   (Sony VGP-BPL9 battery)          .

The section on complications gives further explanations for causes of data remanence.

Countermeasures

Main article: Data erasure

There are three levels commonly recognized for eliminating remnant data      (Sony VGP-BPL11 battery)      :

Clearing

Clearing is the removal of sensitive data from storage devices in such a way that there is assurance that the data may not be reconstructed using normal system functions or software file/data recovery utilities. The data may still be recoverable, but not without special laboratory techniques      (Sony VGP-BPL15 battery)    .

Clearing is typically an administrative protection against accidental disclosure within an organization. For example, before a hard drive is re-used within an organization, its contents may be cleared to prevent their accidental disclosure to the next user     (Dell Inspiron E1505 battery)      .

Purging

Purging or sanitising is the removal of sensitive data from a system or storage device with the intent that the data can not be reconstructed by any known technique. Purging, proportional to the sensitivity of the data, is generally done before releasing media outside of control, such as before discarding old media, or moving media to a computer with different security requirements   (Dell Latitude E6400 battery)    .

Destruction

The storage medium is physically destroyed. Effectiveness of physical destruction varies. Depending on recording density of the medium, and/or the destruction technique, this may leave data recoverable by laboratory methods      (HP Pavilion dv6000 Battery).

Conversely, physical destruction using appropriate techniques is generally considered the most secure method available.

Specific methods

Overwriting

A common method used to counter data remanence is to overwrite the storage medium with new data    (Sony Vaio VGN-FZ31S battery)    .

This is often called wiping or shredding a file or disk. Because such methods can often be implemented in software alone, and may be able to selectively target only part of a medium, it is a popular, low-cost option for some applications. Overwriting is generally an acceptable method of clearing, as long as the media is writable and not damaged     (Sony VGN-FZ31S battery)      .

The simplest overwrite technique writes the same data everywhere—often just a pattern of all zeros. At a minimum, this will prevent the data from being retrieved simply by reading from the medium again using standard system functions.

To counter more advanced data recovery techniques, specific overwrite patterns are often prescribed       (Hp pavilion dv6000 battery)  .

These may be generic patterns intended to eradicate any trace signatures. For example, writing repeated, alternating patterns of ones and zeros may be more effective than zeros alone . Combinations of patterns are frequently specified.

One challenge with an overwrite is that some areas of the disk may be inaccessible, due to media degradation or other errors  (SONY VGN-FZ38M Battery)     .

Software overwrite may also be problematic in high-security environments which require stronger controls on data commingling than can be provided by the software in use. The use of advanced storage technologies may also make file-based overwrite ineffective (SONY VGN-FZ31z Battery)       .

Feasibility of recovering overwritten data

Peter Gutmann investigated data recovery from nominally overwritten media in the mid-1990s. He suggested magnetic force microscopy may be able to recover such data, and developed specific patterns, for specific drive technologies, designed to counter such. These patterns have come to be known as the Gutmann method  (Sony VGN-FZ31Z Battery)    .

Daniel Feenberg, an economist at the private National Bureau of Economic Research, claims that the chances of overwritten data being recovered from a modern hard drive amount to "urban legend". He also points to the "18½ minute gap" Rose Mary Woods created on a tape of Richard Nixon discussing the Watergate break-in     (SONY VGN-FZ31E Battery)      .

Erased information in the gap has not been recovered, and Feenberg claims doing so would be an easy task compared to recovery of a modern high density digital signal.

As of November 2007, the United States Department of Defense considers overwriting acceptable for clearing magnetic media within the same security area/zone, but not as a sanitization method     (SONY  VGN-FZ31J Battery)        .

Onlydegaussing or physical destruction is acceptable for the latter.

On the other hand, according to the 2006 NIST Special Publication 800-88 (p. 7): "Studies have shown that most of today’s media can be effectively cleared by one overwrite" and "for ATA disk drives manufactured after 2001 (over 15 GB) the terms clearing and purging have converged      (SONY VGN-FZ31M Battery)       ."

An analysis by Wright et al. of recovery techniques, including magnetic force microscopy, also concludes that a single wipe is all that is required for modern drives. They point out that the long time required for multiple wipes "has created a situation where many organisations ignore the issue all together – resulting in data leaks and loss  (SONY VGN-FZ31B Battery)    . "

Degaussing

Degaussing is the removal or reduction of a magnetic field of a disk or drive, using a device called a degausser that has been designed for the media being erased. Applied to magnetic media, degaussing may purge an entire media element quickly and effectively      (SONY VGP-BPS13 Battery)     .

Degaussing often renders hard disks inoperable, as it erases low-level formatting that is only done at the factory during manufacturing. It is possible, however, to return the drive to a functional state by having it serviced at the manufacturer. Degaussed floppy disks can generally be reformatted and reused with standard consumer hardware     (Dell Inspiron 1320 Battery)      .

In some high-security environments, one may be required to use a degausser that has been approved for the task. For example, in US government and military jurisdictions, one may be required to use a degausser from the NSA's "Evaluated Products List"  (Dell Inspiron 1320n Battery)     .

Encryption

Encrypting data before it is stored on the medium may mitigate concerns about data remanence. If the decryption key is strong and carefully controlled (i.e., not itself subject to data remanence), it may effectively make any data on the medium unrecoverable    (Dell Inspiron 1464 Battery)       .

Even if the key is stored on the medium, it may prove easier or quicker to overwrite just the key, vs the entire disk.

Encryption may be done on a file-by-file basis, or on the whole disk. Cold boot attacks are one of the few possible methods for subverting a whole-disk encryption method       (Dell Inspiron 1564 Battery)        ,

as there is no possibility of storing the plain text key in an unencrypted section of the medium. However, even this is unlikely and difficult to execute in a non-laboratory situation, as a cold boot attack requires immediate network access to the computer and is only possible within several minutes or even seconds of the system being depowered      (Dell Inspiron 1764 Battery)   ,

depending on the kind of random access memory used. Even then there is still the possibility of the key itself being scrambled or otherwise protected, which may make even this method fail.

Other side-channel attacks, like the use of hardware-based keyloggers or acquisition of a written note containing the decryption key  (Dell Studio 1450 Battery)       ,

may offer a greater chance to success, but do not rely on weaknesses in the cryptographic method employed. As such, their relevance for this article is minor.

Physical destruction

Thorough physical destruction of the entire data storage medium is generally considered the most certain way to counter data remanence     (Dell Studio 1457 Battery)       .

However, the process is generally time-consuming and cumbersome. Physical destruction may require extremely thorough methods, as even a small media fragment may contain large amounts of data.

Specific destruction techniques include    (Dell Latitude D610 Battery)          :

• Physically breaking the media apart, by grinding, shredding, etc.
• Incinerating
• Phase transition (i.e., liquification or vaporization of a solid disk)
• Application of corrosive chemicals, such as acids, to recording surfaces     (Toshiba NB100 Battery)
• For magnetic media, raising its temperature above the Curie point
• For many electric volatile and non-volatile storage mediums, application of extremely high voltage as compared to safe operational specifications   (Toshiba Satellite M65 battery)

Complications

Inaccessible media areas

Storage media may have areas which become inaccessible by normal means. For example, magnetic disks may develop new "bad sectors" after data have been written, and tapes require inter-record gaps       (Toshiba Satellite M60 battery)     .

Modern hard disks often feature automatic remapping of marginal sectors or tracks, which the OS may not even be aware of. This problem is especially significant in solid state drives (SSDs) that rely on relatively large relocated bad block tables. Attempts to counter data remanence by overwriting may not be successful in such situations, as data remnants may persist in such nominally inaccessible areas        (Dell Latitude D830 Battery)     .

Advanced storage systems

Data storage systems with more sophisticated features may make overwrite ineffective, especially on a per-file basis.

Journaling file systems increase the integrity of data by recording write operations in multiple locations, and applying transaction-like semantics    (Dell Latitude D620 Battery)       .

On such systems, data remnants may exist in locations "outside" the nominal file storage location    .

Some file systems implement copy-on-write or built-in revision control, with the intent that writing to a file never overwrites data in-place        (Dell Studio 1735 Battery)      .

Technologies such as RAID and anti-fragmentation techniques may result in file data being written to multiple locations, either by design (for fault tolerance), or as data remnants.

Wear leveling can also defeat data erasure, by relocating blocks between the time when they are originally written and the time when they are overwritten      (Dell Inspiron Mini 10 Battery)      .

Optical media

Optical media are not magnetic and are not affected by degaussing. Write-once optical media (CD-R, DVD-R, etc.) also cannot be purged by overwrite. Read/write optical media, such as CD-RW andDVD-RW, may be receptive to overwriting      (Sony VGN-FW11S Battery)    .

Methods for successfully sanitizing optical discs include delaminating-abrasion of the metallic data layer, shredding, destructive electrical arcing (as by exposure to microwave energy), and submersion in a polycarbonate solvent (e.g., acetone)    (Sony VGN-FW11M Battery)       .

Data in RAM

Data remanence has been observed in static RAM, which is typically considered volatile (i.e., contents are erased with loss of electrical power). In the study, data retention was sometimes observed even at room temperature.

Another study found data remanence in dynamic random access memory (DRAM), again with data retention of seconds to minutes at room temperature and "a full week without refresh when cooled with liquid nitrogen     (Dell Studio 1555 battery)    ."

The study authors were able to use a cold boot attack to recover cryptographic keys for several popular full disk encryption systems. Despite some memory degradation, they were able to take advantage of redundancy in the way keys are stored after they have been expanded for efficient use, such as in key scheduling        (Dell Latitude E5400 Battery)         .

The authors recommend that computers be powered down, rather than be left in a "sleep" state, when not in physical control of the owner, and in some cases such as one where you have the software program Bitlocker, that a boot PIN also be configured.Modern RAM chips have a built-in self-refresh module so they can retain data for as long as they have power supply and a clock signal  (Dell Latitude E4200 Battery)      .

It is also possible to prevent data remanence on RAM by running a memory testing tool, such as Memtest86, in order to overwrite the entire RAM.

Standards

United States

• NIST Special Publication 800-88: Guidelines for Media Sanitization, September 2006   (Dell Vostro A840 Battery)
• DoD 5220.22-M: National Industrial Security Program Operating Manual (NISPOM), February 2006
  • Current editions no longer contain any references to specific sanitization methods. Standards for sanitization are left up to the Cognizant Security Authority     (Dell Inspiron 300M Battery)        .
  • Although the NISPOM text itself never described any specific methods for sanitization, past editions (1995 and 1997)  did contain explicit sanitization methods within the Defense Security Service (DSS) Clearing and Sanitization Matrix inserted after Section 8-306. The DSS still provides this matrix and it continues to specify methods    (Dell Studio 1737 battery)    .
  • As of the Nov 2007 edition of the matrix, overwriting is no longer acceptable for sanitization of magnetic media. Only degaussing (with an NSA approved degausser) or physical destruction is acceptable.
• Army AR380-19 Information Systems Security, February 1998     (Dell Inspiron E1505 battery)
• Air Force AFSSI-5020 Remanence Security, August 1996
• Navy NAVSO P5239-26 Remanence Security, September 1993

Canada

• RCMP B2-002: IT Media Overwrite and Secure Erase Products, May 2009   (Dell Latitude E6400 battery)
• Communications Security Establishment Clearing and Declassifying Electronic Data Storage Devices, July 2006

Data erasure (also called data clearing) is a software-based method of overwriting data that completely destroys all electronic data residing on a hard disk drive or other digital media     (Dell RM791 battery)        .

Permanent data erasure goes beyond basic file deletion commands, which only remove direct pointers to data disk sectors and make data recovery possible with common software tools. Unlike degaussing and physical destruction, which render the storage media unusable, data erasure removes all information while leaving the disk operable, preserving IT assets and the environment (Dell XPS M1530 battery)    .

Software-based overwriting uses a software application to write patterns of meaningless data onto each of a hard drive's sectors. There are key differentiators between data erasure and other overwriting methods, which can leave data intact and raise the risk of data breach or spill, identity theft and failure to achieve regulatory compliance     (Dell XPS M2010 battery)    .

Data erasure also provides multiple overwrites so that it supports recognized government and industry standards. It provides verification of data removal, which is necessary for meeting certain standards.

To protect data on lost or stolen media, some data erasure applications remotely destroy data if the password is incorrectly entered (Dell Vostro 1000 battery)        .

Data erasure tools can also target specific data on a disk for routine erasure, providing a hacking protection method that is less time-consuming than encryption.

Importance

Information technology (IT) assets commonly hold large volumes of confidential data       (Acer Aspire One battery)        .

Social security numbers, credit card numbers, bank details, medical history and classified information are often stored on computer hard drives or servers and can inadvertently or intentionally make their way onto other media such as printer, USB, flash, Zip, Jaz, and REV drives    (Toshiba Satellite P10 Battery)     .

Data breach

Increased storage of sensitive data, combined with rapid technological change and the shorter lifespan of IT assets, has driven the need for permanent data erasure of electronic devices as they are retired or refurbished     (SONY VGN-FZ210CE Battery)   .

Also, compromised networks and laptop theft and loss, as well as that of other portable media, are increasingly common sources of data breaches.

If data erasure does not occur when a disk is retired or lost, an organization or user faces that possibility that data will be stolen and compromised, leading to identity theft, loss of corporate reputation, threats to regulatory compliance and financial impacts     (Dell Precision M70 Battery)     .

Companies have spent nearly $5 million on average to recover when corporate data was lost or stolen. High profile incidents of data theft include:

• Oklahoma Corporation Commission (2008-05-21): Server sold at auction compromises more than 5,000 Social Security numbers      (Toshiba Satellite L305 Battery)       .
• University of Florida College of Medicine, Jacksonville (2008-05-20): Photographs and identifying information of 1,900 on improperly disposed computer.
• Compass Bank (2008-03-21): Stolen hard drive contains 1,000,000 customer records    (Toshiba Satellite T4900 Battery) .
• Lifeblood (2008-02-13): Missing laptops contain personal information including dates of birth and some Social Security numbers of 321,000.
• Hannaford (2008-03-17): Breach exposes 4.2 million credit, debit cards.
• CardSystems Solutions (2005-06-19): Credit card breach exposes 40 million accounts    (Toshiba PA3399U-2BRS battery)  .

Regulatory compliance

Strict industry standards and government regulations are in place that force organizations to mitigate the risk of unauthorized exposure of confidential corporate and government data      (Toshiba Satellite A200 Battery)      .

These regulations include HIPAA (Health Insurance Portability and Accountability Act); FACTA (The Fair and Accurate Credit Transactions Act of 2003); GLB (Gramm-Leach Bliley); Sarbanes-Oxley Act (SOx); and Payment Card Industry Data Security Standards (PCI DSS)       (Toshiba Satellite 1200 Battery)      .

Failure to comply can result in fines and damage to company reputation, as well as civil and criminal liability.

Preserving assets and the environment

Data erasure offers an alternative to physical destruction and degaussing for secure removal of all disk data     (Toshiba Satellite M300 Battery)   .

Physical destruction and degaussing destroy the digital media, requiring disposal and contributing to electronic waste while negatively impacting the carbon footprint of individuals and companies. Hard drives are nearly 100% recyclable and can be collected at no charge from a variety of hard drive recyclers after they have been sanitized  (WD External HDD ---passport essential (500GB/640GB)) .

Limitations

Data erasure through overwriting only works on hard drives that are functioning and writing to all sectors. Bad sectors cannot usually be overwritten but may contain recoverable information. Software driven data erasure could also be compromised by malicious code      (WD External HDD passport essential (250GB/320GB) .

Differentiators

Software-based data erasure uses a special application to write a combination of 1's and 0's onto each hard drive sector. The level of security depends on the number of times the entire hard drive is written over  (WD External HDD ---passport essential SE (750GB/1TB))     .

Full disk overwriting

There are many overwriting programs, but data erasure offers complete security by destroying data on all areas of a hard drive. Disk overwriting programs that cannot access the entire hard drive (WD External HDD ---passport elite(250GB/320GB)) ,

including hidden/locked areas like the host protected area (HPA), device configuration overlay (DCO), and remapped sectors, perform an incomplete erasure, leaving some of the data intact. By accessing the entire hard drive, data erasure eliminates the risk of data remanence    (WD External HDD ---passport elite(500GB/640GB))         .

Data erasure also bypasses the BIOS and OS. Overwriting programs that operate through the BIOS and OS will not always perform a complete erasure due to altered or corrupted BIOS data and may report back a complete and successful erasure even if they do not access the entire hard disk, leaving data accessible             (WD External HDD ---passport studio for Mac(320GB/500GB))           .

Hardware support

Data erasure can be deployed over a network to target multiple PCs rather than having to erase each one sequentially. In contrast with DOS-based overwriting programs that may not detect all network hardware      (WD External HDD ---passport studio for Mac(500GB/640GB)),

Linux-based data erasure software supports high-end server and storage area network (SAN) environments with hardware support for Serial ATA, Serial Attached SCSI (SAS) and Fibre Channel disks and remapped sectors. It operates directly with sector sizes such as 520, 524, and 528, removing the need to first reformat back to 512 sector size  (WD External HDD ---Elements series(250GB/320GB))  .

Standards

Many government and industry standards exist for software-based overwriting that removes data. A key factor in meeting these standards is the number of times the data is overwritten     (WD External HDD ---Elements SE(500GB/640GB))        .

Also, some standards require a method to verify that all data has been removed from the entire hard drive and to view the overwrite pattern. Complete data erasure should account for hidden areas, typically DCO, HPA and remapped sectors     (WD External HDD ---Elements SE(750GB/1TB))       .

The 1995 edition of the National Industrial Security Program Operating Manual (DoD 5220.22-M) permitted the use of overwriting techniques to sanitize some types of media by writing all addressable locations with a character, its complement, and then a random character      (WD External HDD --- Elements desktop(500GB/640GB))      .

This provision was removed in a 2001 change to the manual and was never permitted for Top Secret media, but it is still listed as a technique by many providers of data erasure software.

Data erasure software should provide the user with a validation certificate indicating that the overwriting procedure was completed properly     (WD External HDD --- Elements desktop(750GB/1TB))    .

Data erasure software should also comply with requirements to erase hidden areas, provide a defects log list, and list bad sectors that could not be overwritten.

Data can sometimes be recovered from a broken hard drive  (WD External HDD --- Elements desktop(1.5 TB/2TB))  .

However, if the platters on a hard drive are damaged, such as by drilling a hole through the drive (and the platters inside), then data can only be recovered by bit-by-bit analysis of each platter with advanced forensic technology. Seagate is the only company in the world to have credibly claimed such technology, although some governments may also be able to do this (WD External HDD ---passport essential SE (750GB/1TB)--USB 3.0)      .

Number of overwrites needed

Data on floppy disks can sometimes be recovered by forensic analysis even after the disks have been overwritten once with zeros (or random zeros and ones). This is not the case with modern hard drives   (WD External HDD ---passport essential (500GB/640GB))  :

• According to the 2006 NIST Special Publication 800-88 Section 2.3 (p. 6): "Basically the change in track density and the related changes in the storage medium have created a situation where the acts of clearing and purging the media have converged     (WD External HDD ---passport for Mac(320GB/500GB)).

That is, for ATA disk drives manufactured after 2001 (over 15GB) clearing by overwriting the media once is adequate to protect the media from both keyboard and laboratory attack      (WD External HDD ---passport for Mac(640GB/1TB))    ."

• According to the 2006 CMRR Tutorial on Disk Drive Data Sanitization Document (p. 8): "Secure erase does a single on-track erasure of the data on the disk drive. The U.S. National Security Agency published an Information Assurance Approval of single pass overwrite, after technical testing at CMRR showed that multiple on-track overwrite passes gave no additional erasure    (WD External HDD ---My book essential 4 generation(640GB/1TB).

• re erase" is a utility built into modern ATA hard drives that overwrites all data on a disk, including remapped (error) sectors.

• Further analysis by Wright et al. seems to also indicate that one overwrite is all that is generally required (WD External HDD ---My book essential 4 generation( 1.5TB/2TB))  .

Disk formatting is also part of a process involving rebuilding an entire disk from scratch. A variety of utilities and programs exist for this task; pictured to the right is the iconic FORMAT.COM of DOS  .

History

Modern HDDs, such as SAS and SATA drives, appear at their interfaces as a contiguous set of fixed size logical blocks; typically 512 bytes long but the industry is in the process of changing to 4,096 byte logical blocks (Dell Studio XPS 1640 Battery) .

The earliest disk drives also had fixed block sizes (e.g. IBM 350 disk storage unit block size was 100 6 bit characters) but starting with the 1301 IBM marketed subsystems that featured variable block sizes - a particular track could have blocks of different sizes. The disk subsystems on the IBM System/360 expanded this concept in the form of Count Key Data (CKD) and later Extended Count Key Data (ECKD)  (Dell Studio XPS 1340 Battery)    ;

however the use of variable block size in HDDs fell out of use in the 1990s; one of the last HDDs to support variable block size was the IBM 3390 Model 9, announced May 1993

Floppy disks generally only used fixed block sizes but these sizes were a function of the host controller so that a particular type of media (e.g., 5¼-inch DSDD) would have different block sizes depending upon the host's controller       (Dell Vostro 1710 Battery)   .

Optical disks generally only use fixed block sizes.

Two levels of formatting

Formatting a disk for use by an operating system and its applications and files involves two quite different types of formatting     (Sony VGP-BPS13 battery)       .

First, a low-level (closer to the hardware) formatting program will mark the surface of the disk with sector numbers and other information to be used later, in normal operations, by the disk controller. This is intended to be the permanent foundation of the disk, and is often completed at the factory     (Sony VGP-BPS13/B battery)    .

High-level formatting occurs during operating system installation, or when adding a new disk. This inscribes the file system format. Disk and distributed file system will specify an optional boot block, and various volume and directory information for the operating system    (Sony VGP-BPS13/S battery)    .

Low-level formatting of floppy disks

The low-level format of floppy disks (and early hard disks) is performed by the disk drive's controller.

The process is most easily described with a standard 1.44 MB floppy disk in mind. Low-level formatting of the floppy disk, normally writes 18 sectors of 512 bytes to each of 160 tracks (80 on each side) of the floppy disk, providing 1,474,560 bytes of storage on the disk     (Sony VGP-BPS13A/B battery)    .

Physical sectors are actually larger than 512 bytes, as in addition to the 512 byte data field they include a sector identifier field, CRC bytes (in some cases error correction bytes) and gaps between the fields. These additional bytes are not normally included in the quoted figure for overall storage capacity of the disk     (Sony VGP-BPS13B/B battery) .

Different low-level formats can be used on the same media; for example, large records can be used to cut down on inter-record gap size.

Several freeware, shareware and free software programs (e.g. GParted, FDFORMAT, NFORMAT and 2M) allowed considerably more control over formatting, allowing the formatting of high-density 3.5" disks with a capacity up to 2 MB     (Sony VGP-BPS13B/B battery) .

Techniques used include:

• head/track sector skew (moving the sector numbering forward at side change and track stepping to reduce mechanical delay),
• interleaving sectors (to minimize sector gap and thereby allowing the number of sectors per track to be increased) (Sony VGP-BPL9 battery)      ,
• increasing the number of sectors per track (while a normal 1.44 MB format uses 18 sectors per track, it is possible to increase this to a maximum of 21), and
• increasing the number of tracks (most drives could tolerate extension to 82 tracks – though some could handle more, others could jam)    (Sony VGP-BPL11 battery)    .

Linux supports a variety of sector sizes, and DOS and Windows support a large-record-size DMF-formatted floppy format.

Low-level formatting (LLF) of hard disks

User instigated low-level formatting (LLF) of hard disk drives was common for minicomputer and personal computer systems until the 1990s     (Sony VGP-BPL15 battery)   .

IBM and other mainframe system vendors typically supplied their hard disk drives (or media in the case of removable media HDDs) with a low-level format. Typically this involved subdividing each track on the disk into one or more blocks which would contain the user data and associated control information    (Dell Inspiron E1505 battery)    .

Different computers used different block sizes and IBM notably used variable block sizes but the popularity of the IBM PC caused the industry to adopt a standard of 512 user data bytes per block by the middle 1980s.

Depending upon the system, low-level formatting was generally done by an operating system system utility    (Dell Latitude E6400 battery)     .

IBM compatible PCs used the BIOS which is involved using the MS-DOS debug program to transfer control to a routine hidden at different addresses in different BIOSs . Low-level format function can also be called as "erase" or "wipe" in different tools. For best results it's highly recommended to use tools created by hard disk's manufacturer    (HP Pavilion dv6000 Battery) .

Transition away from LLF

Starting in the late 1980s, driven by the volume of IBM compatible PCs, HDDs became routinely available pre-formatted with a compatible low-level format. At the same time, the industry moved from historical (dumb) bit serial interfaces to modern (intelligent) bit serial interfaces and Word serial interfaces wherein the low level format was performed at the factory  (Sony Vaio VGN-FZ31S battery)    .

Today, an end-user, in most cases, should never perform a low-level formatting of an IDE or ATA hard drive, and in fact it is often not possible to do so on modern hard drives outside of the factory    (Sony VGN-FZ31S battery)     .

Disk reinitialization

While it is impossible to perform an LLF on most modern hard drives (since the mid-1990s) outside the factory, the term "low-level format" is still being used (erroneously) for what should be called thereinitialization of a hard drive to its factory configuration (and even these terms may be misunderstood)    (Hp pavilion dv6000 battery)     .

Reinitialization should include identifying (and sparing out if possible) any sectors which cannot be written to and read back from the drive, correctly. The term has, however, been used by some to refer to only a portion of that process, in which every sector of the drive is written to; usually by writing a zero byte to every addressable location on the disk, sometimes called zero-filling (SONY VGN-FZ38M Battery)   .

The present ambiguity in the term "low-level format" seems to be due to both inconsistent documentation on web sites and the belief by many users that any process below a "high-level (file system) format" must be called a low-level format. Instead of correcting this mistaken idea (by clearly stating such a process cannot be performed on specific drives)  (SONY VGN-FZ31z Battery)   ,

various drive manufacturers have actually described reinitialization software as LLF utilities on their web sites. Since users generally have no way to determine the difference between a true LLF and reinitialization (they simply observe running the software results in a hard disk that must be partitioned and "high-level formatted")       (Sony VGN-FZ31Z Battery)      ,

both the misinformed user and mixed signals from various drive manufacturers have perpetuated this error. Note: Whatever possible misuse of such terms may exist (search hard drive manufacturers' web sites for all these terms), many sites do make such reinitialization utilities available (possibly as bootable floppy diskette or CD image files)       (SONY VGN-FZ31E Battery)  ,

to both overwrite every byte and check for damaged sectors on the hard disk.

One popular method for performing only the "zero-fill" operation on a hard disk is by writing zero-bytes to the drive using the Unix dd utility (available under Linux as well) with the "/dev/zero" stream as the input file (if=) and the drive itself (either the whole disk, or a specific partition) as the output file (of=)    (SONY  VGN-FZ31J Battery)       .

Another method for SCSI disks may use the sg_format command to issue a low level "SCSI FORMAT UNIT" command.

High-level formatting

High-level formatting is the process of setting up an empty file system on the disk and installing a boot sector. This alone takes little time, and is sometimes referred to as a "quick format"     (SONY VGN-FZ31M Battery)     .

In addition, the entire disk may optionally be scanned for defects, which takes considerably longer, up to several hours on larger hard disks.

In the case of floppy disks, both high- and low-level formatting are customarily done in one pass by the software. In recent years, most floppies have shipped pre-formatted from the factory as DOSFAT12 floppies   (SONY VGN-FZ31B Battery)    .

It is possible to format them again to other formats, if necessary.

Host Protected Area

The host protected area, sometimes referred to as hidden protected area , is an area of a hard drive that is high level formatted so that the area is not normally visible to its operating system (OS)     (SONY VGP-BPS13 Battery)     .

Reformatting

"Reformatting" refers to a high-level format performed on a functioning disk drive to free the contents of it medium. "Reformatting" is unique to each operating system because what actually is done to existing data varies by OS. The most important aspect of the process is that it frees disk space for use by other data    (Dell Inspiron 1320 Battery)      .

To actually "erase" everything requires overwriting each block of data on the medium; something that is not done by many high-level formatting utilities.

Reformatting often carries the implication that the operating system and all other software will be reinstalled after the format is complete      (Dell Inspiron 1320n Battery)    .

Rather than fixing an installation suffering from malfunction or security compromise, it is sometimes judged easier to simply reformat everything and start from scratch. Various colloquialism exist for this process, such as "wipe and reload", "nuke and pave", "reimage", etc   (Dell Inspiron 1464 Battery)  .

Formatting

In DOS, OS/2 and Windows

Under MS-DOS, PC-DOS, OS/2 and Microsoft Windows, disk formatting can be performed by the format command   (Dell Inspiron 1564 Battery)      .

The format program usually asks for confirmation beforehand to prevent accidental removal of data, but some versions of DOS have an undocumented /AUTOTEST option; if used, the usual confirmation is skipped and the format begins right away. The WM/ FormatC macro virus uses this command to format the C: drive as soon as a document is opened    (Dell Inspiron 1764 Battery)  .

There is also the undocumented /U parameter that performs an unconditional format which under most circumstances overwrites the entire partition,preventing the recovery of data through software. Note however that the /U switch only works reliably with floppy diskettes (technically because unless /Q is used, floppies are always low-level formatted in addition to high-level formatted) (Dell Studio 1450 Battery)   .

Under certain circumstances with hard drive partitions, however, the /U switch merely prevents the creation ofunformat information in the partition to be formatted while otherwise leaving the partition's contents entirely intact (still on disk but marked deleted)    (Dell Studio 1457 Battery)     .

In such cases, the user's data remains ripe for recovery with specialist tools such as EnCase or disk editors. Reliance upon /U for secure overwriting of hard drive partitions is therefore inadvisable, and purpose-built tools such as DBAN should be considered instead    (Dell Latitude D610 Battery)    .

Under OS/2, if you use the /L parameter, which specifies a long format, then format will overwrite the entire partition or logical drive.

In Unix and similar operating systems

Formatting disks on these systems is traditionally done using the mkfs command    (Toshiba NB100 Battery)     .

On Linux (and potentially other systems as well) mkfs is typically a wrapper around filesystem-specific commands which have the name mkfs.fsname, where fsname is the name of the filesystem with which to format the disk     (Toshiba Satellite M65 battery)   .

Some Unix-like operating systems have higher-level formatting tools, usually for the purpose of making disk formatting easier and/or allowing the user to partition the disk with the same tool. Examples include GNU Parted (and it's various GUI frontends such as GParted and the KDE Partition Manager) and the Disk Utility application on Mac OS X    (Toshiba Satellite M60 battery)    .

Some filesystems which are not supported by certain implementations of mkfs have their own manipulation tools; for example Ntfsprogs provides a format utility for the NTFS filesystem.

Recovery of data from a formatted disk

As with regular deletion, data on a disk is not fully destroyed during a high-level format     (Dell Latitude D830 Battery)     .

Instead, the area on the disk containing the data is merely marked as available (in whatever file system structure the format uses), and retains the old data until it is overwritten. If the formatting is done with a different file system than previously existed in the partition, some data may be overwritten that wouldn't be if the same file system had been used (Dell Studio 1735 Battery)    .

However, under some file systems (e.g., NTFS, but not FAT), the file indexes (such as $MFTs under NTFS, "inodes" under ext2/3, etc.) may not be written to the same exact locations. And if the partition size is increased, even FAT file systems will overwrite more data at the beginning of that new partition      (Dell Latitude D620 Battery)       .

From the perspective of preventing the recovery of sensitive data through recovery tools, the data must either be completely overwritten (every sector) with random data before the format, or the format program itself must perform this overwriting, as the DOS FORMAT command did with floppy diskettes, filling every data sector with the byte value F6 in hex   (Dell Inspiron Mini 10 Battery)    .

Data recovery

Data recovery is the process of salvaging data from damaged, failed, corrupted, or inaccessible secondary storage media when it cannot be accessed normally. Often the data are being salvaged from storage media such as hard disk drives, storage tapes, CDs, DVDs, RAID, and other electronics      (Sony VGN-FW11S Battery)      .

Recovery may be required due to physical damage to the storage device or logical damage to the file system that prevents it from being mounted by the host operating system.

The most common "data recovery" scenario involves an operating system (OS) failure (typically on a single-disk, single-partition, single-OS system), in which case the goal is simply to copy all wanted files to another disk     (Sony VGN-FW11M Battery)     .

This can be easily accomplished with a Live CD, most of which provide a means to mount the system drive and backup disks or removable media, and to move the files from the system disk to the backup media with a file manager or optical disc authoring software     (Dell Studio 1555 battery)    .

Such cases can often be mitigated by disk partitioning and consistently storing valuable data files (or copies of them) on a different partition from the replaceable OS system files.

Another scenario involves a disk-level failure, such as a compromised file system or disk partition or a hard disk failure      (Dell Latitude E5400 Battery)      .

In any of these cases, the data cannot be easily read. Depending on the situation, solutions involve repairing the file system, partition table or master boot record, or hard disk recovery techniques ranging from software-based recovery of corrupted data to hardware replacement on a physically damaged disk    (Dell Latitude E4200 Battery)       .

If hard disk recovery is necessary, the disk itself has typically failed permanently, and the focus is rather on a one-time recovery, salvaging whatever data can be read.

In a third scenario, files have been "deleted" from a storage medium       (Dell Vostro A840 Battery)      .

Typically, deleted files are not erased immediately; instead, references to them in the directory structure are removed, and the space they occupy is made available for later overwriting. In the meantime, the original file may be restored. Although there is some confusion over the term, "data recovery" may also be used in the context of forensic applications or espionage    (Dell Inspiron 300M Battery)   .

Recovering data after physical damage

A wide variety of failures can cause physical damage to storage media. CD-ROMs can have their metallic substrate or dye layer scratched off; hard disks can suffer any of several mechanical failures, such as head crashes and failed motors; tapes can simply break   (Dell Studio 1737 battery)     .

Physical damage always causes at least some data loss, and in many cases the logical structures of the file system are damaged as well. Any logical damage must be dealt with before files can be salvaged from the failed media.

Most physical damage cannot be repaired by end users     (Dell Inspiron E1505 battery)     .

For example, opening a hard disk in a normal environment can allow airborne dust to settle on the platter and become caught between the platter and the read/write head, causing new head crashes that further damage the platter and thus compromise the recovery process     (Dell Latitude E6400 battery)       .

Furthermore, end users generally do not have the hardware or technical expertise required to make these repairs. Consequently, costly data recovery companies are often employed to salvage important data.

Recovery techniques

Recovering data from physically-damaged hardware can involve multiple techniques      (Dell RM791 battery)   .

Some damage can be repaired by replacing parts in the hard disk. This alone may make the disk usable, but there may still be logical damage. A specialized disk-imaging procedure is used to recover every readable bit from the surface. Once this image is acquired and saved on a reliable medium, the image can be safely analysed for logical damage and will possibly allow for much of the original file system to be reconstructed     (Dell XPS M1530 battery)         .

Hardware repair

Examples of physical recovery procedures are: removing a damaged PCB (printed circuit board) and replacing it with a matching PCB from a healthy drive, performing a live PCB swap (in which the System Area of the HDD is damaged on the target drive which is then instead read from the donor drive     (Dell XPS M2010 battery)    ,

the PCB then disconnected while still under power and transferred to the target drive), read/write head assembly with matching parts from a healthy drive, removing the hard disk platters from the original damaged drive and installing them into a healthy drive, and often a combination of all of these procedures      (Dell Vostro 1000 battery)       .

Some data recovery companies have procedures that are highly technical in nature and are not recommended for an untrained individual. Each of them will void the manufacturer's warranty. For companies who will not void a warranty, see companies such as Kroll Ontrack, SalvageData, and DriveSavers       (Acer Aspire One battery)      .

Recovering from logical (non-hardware) damage

Overwritten data

See also: Data erasure

When data have been physically overwritten on a hard disk it is generally assumed that the previous data are no longer possible to recover   (Toshiba Satellite P10 Battery)     .

In 1996,Peter Gutmann, a computer scientist , presented a paper that suggested overwritten data could be recovered through the use of Scanning transmission electron microscopy. In 2001, he presented another paper on a similar topic. Substantial criticism has followed, primarily dealing with the lack of any concrete examples of significant amounts of overwritten data being recovered    (SONY VGN-FZ210CE Battery)  .

To guard against this type of data recovery, he and Colin Plumb designed the Gutmann method, which is used by several disk scrubbing software packages.

Although Gutmann's theory may be correct, there's no practical evidence that overwritten data can be recovered    (Dell Precision M70 Battery)     .

Moreover, there are good reasons to think that it cannot.

Corrupt filesystems

In some cases, data on a hard drive can be unreadable due to damage to the filesystem      (Toshiba Satellite L305 Battery)    .

In the majority of these cases, at least a portion of the original data can be recovered by repairing the damaged filesystem using specialized data recovery software. This type of data recovery can be performed by knowledgeable end-users as it requires no special physical equipment      (Toshiba Satellite T4900 Battery)       .

However, more serious cases can still require expert intervention.

Online Data Recovery

"Online" or "Remote" data recovery is yet another method to restore the lost or deleted data       (Toshiba PA3399U-2BRS battery)  .

It is same as performing the regular software based recoveries except that this kind of recovery is performed over the Internet without physically having the drive or computer in possession. The recovery technician sitting somewhere else gains access to user's computer and complete the recovery job online      (Toshiba Satellite A200 Battery)     .

In this scenario, the user doesn't have to travel or send the media to anywhere physically.

Although online data recovery is convenient and useful in many cases, it still carries some points making it less popular than the classic data recovery methods     (Toshiba Satellite 1200 Battery)     .

First of all, it requires a stable broadband Internet connection for it to be performed correctly, which many third world countries still lack. Also, it cannot be performed in case of physical damage to media and for such cases, the traditional in-lab recovery has to take place     (Toshiba Satellite M300 Battery)      .

Nokia Siemens Networks (previously Nokia Networks) provides wireless and fixed network infrastructure, communications and networks service platforms, as well as professional services to operators and service providers       (Dell XPS M1210 Battery) http://www.hdd-shop.co.uk/ .

Nokia Siemens Networks focuses in GSM, EDGE, 3G/W-CDMA and WiMAX radio access networks; core networks with increasing IP and multiaccess capabilities; and services.

On June 19, 2006 Nokia and Siemens AG announced the companies are to merge their mobile and fixed-line phone network equipment businesses to create one of the world's largest network firms, called Nokia Siemens Networks   (Dell Studio XPS 1340 Battery)     .

The Nokia Siemens Networks brand identity was subsequently launched at the 3GSM World Congress in Barcelona in February 2007.

As of March 2009, Nokia Siemens Networks serves more than 600 operator customers in more than 150 countries, with over 1.5 billion people connected through its networks  (Dell Studio XPS 1640 Battery)      .

Navteq

Navteq is a Chicago, Illinois-based provider of digital map data and location-based content and services for automotive navigation systems, mobile navigation devices, Internet-based mapping applications, and government and business solutions. Navteq was acquired by Nokia on October 1, 2007  (Dell Vostro 1710 Battery)       .

Navteq’s map data is part of the Nokia Maps online service where users can download maps, use voice-guided navigation and other context-aware web services.Nokia Maps is part of the Ovi brand of Nokia's Internet based online services.

Corporate governance

The control and management of Nokia is divided among the shareholders at a general meeting and the Group Executive Board (left),under the direction of the Board of Directors (right)        (Sony VGP-BPS13 battery)      .

The Chairman and the rest of the Group Executive Board members are appointed by the Board of Directors. Only the Chairman of the Group Executive Board can belong to both, the Board of Directors and the Group Executive Board. The Board of Directors' committees consist of the Audit Committee, the Personnel Committee and the Corporate Governance and No    ation Committee   (Sony VGP-BPS13/B battery).

The operations of the company are managed within the framework set by the Finnish Companies Act, Nokia's Articles of Associationand Corporate Governance Guidelines, and related Board of Directors adopted charters  (Sony VGP-BPS13/S battery) .

Logos

Stock

Nokia, a public limited liability company, is the oldest company listed under the same name on the Helsinki Stock Exchange (since 1915). Nokia’s shares are also listed on the Frankfurt Stock Exchange (since 1988) and New York Stock Exchange (since 1994)   (Sony VGP-BPS13A/B battery)     .

Corporate culture

The Nokia House, Nokia's head office in Keilaniemi,Espoo, Finland.

Nokia's official corporate culture manifesto, The Nokia Way, emphasises the speed and flexibility of decision-making in a flat, networked organization, although the corporation's size necessarily imposes a certain amount of bureaucracy     (Sony VGP-BPS13B/B battery)     .

The official business language of Nokia is English. All documentation is written in English, and is used in official intra-company spoken communication and e-mail.

Until May 2007, the Nokia Values were Customer Satisfaction, Respect, Achievement, and Renewal   (Sony VGP-BPS13B/B battery) .

In May 2007, Nokia redefined its values after initiating a series of discussions worldwide as to what the new values of the company should be. Based on the employee suggestions, the new values were defined as: Engaging You, Achieving Together, Passion for Innovation and Very Human        (Sony VGP-BPL9 battery)    .

Online services

mobi and the Mobile Web

Nokia was the first proponent of a Top Level Domain (TLD) specifically for the Mobile Web and, as a result, was instrumental in the launch of the.mobi domain name extension in September 2006 as an official backer    (Sony VGP-BPL11 battery)    .

Since then, Nokia has launched the largest mobile portal, Nokia.mobi, which receives over 100 million visits a month.It followed that with the launch of a mobile Ad Service to cater to the growing demand for mobile advertisement.

Ovi, announced on August 29, 2007, is the name for Nokia's "umbrella concept" Internet services   (Sony VGP-BPL15 battery)     .

Centered on Ovi.com, it is marketed as a "personal dashboard" where users can share photos with friends, download music, maps and games directly to their phones and access third-party services like Yahoo's Flickr photo site. It has some significance in that Nokia is moving deeper into the world of Internet services, where head-on competition with Microsoft, Google and Apple is inevitable    (Dell Inspiron E1505 battery)   .

The services offered through Ovi include the Ovi Store (Nokia's application store), the Nokia Music Store, Nokia Maps, Ovi Mail, the N-Gage mobile gaming platform available for several S60 smartphones, Ovi Share, Ovi Files, and Contacts and Calendar. The Ovi Store, the Ovi application store was launched in May 2009     (Dell Latitude E6400 battery)     .

Prior to opening the Ovi Store, Nokia integrated its software Download! store, the stripped-down MOSH repository and the widget service WidSets into it.

On March 23, 2010, Nokia announced launch of its online magazine called the Nokia Ovi       (HP Pavilion dv6000 Battery) .

The 44-page magazine contains articles on products by Nokia, what Ovi stands for , tips and tricks on the usage of Nokia mini laptop Booklet 3G, latest reviews of mobile applications, news about the mobile maker's services and apps such as Ovi maps, files and mail. Users can download the magazine as a PDF or view it online from the Nokia website      (Sony Vaio VGN-FZ31S battery)     .

My Nokia

Nokia offers a free personalised service to its subscribers called My Nokia (located at my.nokia.com). Registered My Nokia users can avail free services as follows:

• Tips & tricks alerts through web, e-mail and also mobile text message       (Sony VGN-FZ31S battery)      .
• My Nokia Backup: A free online backup service for mobile contacts, calendar logs and also various other files. This service needs GPRS connection.
• Numerous ringtones, wallpapers, screensavers, games and other things can be downloaded free of cost     (Hp pavilion dv6000 battery)      .

Comes With Music

On December 4, 2007, Nokia unveiled their plans for the "Nokia Comes With Music" initiative, a program that would partner with Universal Music Group International, Sony BMG, Warner Music Group, and EMI as well as hundreds of Independent labels and music aggregators to bundle 12, 18, or 24 months worth of unlimited free music downloads with the purchase of a Nokia Comes With Music edition phone  (SONY VGN-FZ38M Battery)    .

Following the termination of the year of free downloads, tracks can be kept without having to renew the subscription. Downloads are both PC and mobile-based.

Nokia Messaging

On August 13, 2008, Nokia launched a beta release of "Nokia Email service", a new push e-mail service, since graduated as part of Nokia Messaging      (SONY VGN-FZ31z Battery)     .

Nokia Messaging operates as a centralised, hosted service that acts as a proxy between the Nokia Messaging client and the user's e-mail server. It does not allow for a direct connection between the phone and the e-mail server, and is therefore required to send e-mail credentials to Nokia's servers       (Sony VGN-FZ31Z Battery)      .

IMAP is used as the protocol to transfer emails between the client and the server.

Controversy

NSN's provision of intercept capability to Iran

In 2008, Nokia Siemens Networks, a joint venture between Nokia and Siemens AG, reportedly provided Iran's monopoly telecom company with technology that allowed it to intercept the Internet communications of its citizens to an unprecedented degree   (SONY VGN-FZ31E Battery)    .

The technology reportedly allowed it to use deep packet inspection to read and even change the content of everything from "e-mails and Internet phone calls to images and messages on social-networking sites such as Facebook and Twitter". The technology "enables authorities to not only block communication but to monitor it to gather information about individuals   (SONY  VGN-FZ31J Battery) ,

as well as alter it for disinformation purposes," expert insiders told The Wall Street Journal. During the post-election protests in Iran in June 2009, Iran's Internet access was reported to have slowed to less than a tenth of its normal speeds, and experts suspected this was due to the use of the interception technology      (SONY VGN-FZ31M Battery)  .

The joint venture company, Nokia Siemens Networks, asserted in a press release that it provided Iran only with a 'lawful intercept capability' "solely for monitoring of local voice calls". "Nokia Siemens Networks has not provided any deep packet inspection, web censorship or Internet filtering capability to Iran," it said      (SONY VAIO VGN-FZ38M Battery)     .

In July 2009, Nokia began to experience a boycott of their products and services in Iran. The boycott was led by consumers sympathetic to the post-election protest movement and targeted at those companies deemed to be collaborating with the Islamic regime. Demand for handsets fell and users began shunning SMS messaging   (SONY VGN-FZ31B Battery)     .

Lex Nokia

In 2009, Nokia heavily supported the passing of a law in Finland that allows companies to monitor their employees’ electronic communications in cases of suspected information leaking. Contrary to rumors, Nokia denied that the company would have considered moving its head office out of Finland if laws on electronic surveillance were not changed       (SONY VGP-BPS13 Battery)  .

The law was enacted, but with strict requirements for implementation of its provisions. As of 2010, the law has become a dead letter; no corporation has implemented it. The Finnish media dubbed the name Lex Nokia for this law, named after the Finnish copyright law (the so-called Lex Karpela) a few years back      (Dell Inspiron 1320 Battery)  .

Nokia–Apple patent dispute

In October 2009, Nokia filed a lawsuit against Apple Inc. in the U.S. District Court of Delaware citing Apple infringed on 10 of its patents related to wireless communication including data transfer. Apple was quick to respond with a countersuit filed in December 2009 accusing Nokia of 11 patent infringements      (Dell Inspiron 1320n Battery)     .

Apple’s General Counsel, Bruce Sewell went a step further by stating, "Other companies must compete with us by inventing their own technologies, not just by stealing ours." This resulted in an ugly spat between the two telecom majors with Nokia filing another suit, this time with the U.S    (Dell Inspiron 1464 Battery)      .

International Trade Commission (ITC), alleging Apple of infringing its patents in "virtually all of its mobile phones, portable music players, and computers." Nokia went on to ask the court to bar all U.S. imports of the Apple products including the iPhone, Mac and the iPod. Apple countersued by filing a complaint with the ITC in January 2010, the details of which are yet to be confirmed     (Dell Inspiron 1564 Battery)    .

Environmental record

Electronic products such as cell phones impact the environment both during production and after their useful life when they are discarded and turned into electronic waste. Nokia tops Greenpeace’s Guide to Greener Electronics of May 2010 that ranks 18 electronics manufacturers according to their policies on toxic chemicals, recycling and climate change       (Dell Inspiron 1764 Battery) .

All of Nokia’s mobile phones are free of toxic polyvinyl chloride (PVC) since the end of 2005 and free of brominated flame retardants (BFRs) since 2010.

Nokia’s voluntary take-back programme to recycle old mobile phones spans 84 countries with almost 5,000 collection points    (Dell Studio 1450 Battery)     .

However, the recycling rate of Nokia phones was only 3–5% in 2008, according to a global consumer survey released by Nokia. The majority of old mobile phones are simply lying in drawers at home and very few old devices, about 4%, are being thrown into landfill and not recycled     (Dell Studio 1457 Battery)  .

All of Nokia’s new models of chargers meet or exceed the Energy Star requirements.Nokia aims to reduce its carbon dioxide emissions by at least 18 percent in 2010 from a baseline year of 2006 and cover 50 percent of its energy needs through renewable energy sources   (Dell Latitude D610 Battery)    .

Greenpeace is challenging the company to use its influence at the political level as number 85 on the Fortune 500 to advocate for climate legislation and call for global greenhouse gas emissions to peak by 2015.

Nokia is researching the use of recycled plastics in its products, which are currently used only in packaging but not yet in mobile phones      (Toshiba NB100 Battery)    .

Since 2001, Nokia has provided eco declarations of all its products and since May 2010 provides Eco profiles for all its new products.In an effort to further reduce their environmental impact in the future, Nokia released a new phone concept, Remade, in February 2008       (Toshiba Satellite M65 battery)    .

The phone has been constructed of solely recyclable materials. The outer part of the phone is made from recycled materials such as aluminium cans, plastic bottles, and used car tires. The screen is constructed of recycled glass, and the hinges have been created from rubber tires     (Toshiba Satellite M60 battery)   .

The interior of the phone is entirely constructed with refurbished phone parts, and there is a feature that encourages energy saving habits by reducing the backlight to the ideal level, which then allows the battery to last longer without frequent charges    (WD External HDD passport essential (500GB),(WD External HDD passport essential (250GB/320GB))

.

The touchscreen has two main attributes. First, it enables one to interact directly with what is displayed, rather than indirectly with a cursor controlled by a mouse or touchpad. Secondly, it lets one do so without requiring any intermediate device that would need to be held in the hand. Such displays can be attached to computers, or to networks as terminals    (Dell Studio XPS 1340 Battery)      .

They also play a prominent role in the design of digital appliances such as the personal digital assistant (PDA), satellite navigation devices, mobile phones, and video games      (Dell Studio XPS 1640 Battery)       .

History

The prototype x-y mutual capacitance touchscreen (left) developed at CERN in 1977 by Bent Stumpe, a Danish electronics engineer, for the control room of CERN’s accelerator SPS (Super Proton Synchrotron). This was a further development of the self capacitance screen(right), also developed at CERN in 1972        (Dell Vostro 1710 Battery)      .

In 1971, the first "touch sensor" was developed by Doctor Sam Hurst (founder of Elographics) while he was an instructor at the University of Kentucky. This sensor, called the "Elograph," was patented by The University of Kentucky Research Foundation. The "Elograph" was not transparent like modern touch screens; however, it was a significant milestone in touch screen technology    (Sony VGP-BPS13 battery)     .

In 1974, the first true touch screen incorporating a transparent surface was developed by Sam Hurst and Elographics. In 1977, Elographics developed and patented five-wire resistive technology, the most popular touch screen technology in use today  (Sony VGP-BPS13/B battery)    .

Touchscreens first gained some visibility with the invention of the computer-assisted learning terminal, which came out in 1975 as part of the PLATO project. Touchscreens have subsequently become familiar in everyday life. Companies use touch screens for kiosk systems in retail and tourist settings, point of sale systems        (Sony VGP-BPS13/S battery)      ,

ATMs, and PDAs, where a stylus is sometimes used to manipulate the GUI and to enter data. The popularity of smart phones, PDAs, portable game consoles and many types of information appliances is driving the demand for, and acceptance of, touchscreens  (Sony VGP-BPS13A/B battery)          .

From 1979–1985, the Fairlight CMI (and Fairlight CMI IIx) was a high-end musical sampling and re-synthesis workstation that utilized light pen technology, with which the user could allocate and manipulate sample and synthesis data, as well as access different menus within its OS by touching the screen with the light pen        (Sony VGP-BPS13B/B battery)       .

The later Fairlight series III models used a graphics tablet in place of the light pen.

The HP-150 from 1983 was one of the world's earliest commercial touchscreen computer. It did not have a touchscreen in the strict sense; instead, it had a 9"Sony Cathode Ray Tube (CRT) surrounded by infrared transmitters and receivers, which detected the position of any non-transparent object on the screen     (Sony VGP-BPS13B/B battery)      .

Until recently, most consumer touchscreens could only sense one point of contact at a time, and few have had the capability to sense how hard one is touching. This is starting to change with the commercialization of multi-touch technology         (Sony VGP-BPL9 battery)          .

Touchscreens are popular in hospitality, and in heavy industry, as well as kiosks such as museum displays or room automation, where keyboard and mouse systems do not allow a suitably intuitive, rapid, or accurate interaction by the user with the display's content        .

Historically, the touchscreen sensor and its accompanying controller-based firmware have been made available by a wide array of after-market system integrators, and not by display, chip, or motherboard manufacturers  (Sony VGP-BPL11 battery)     .

Display manufacturers and chip manufacturers worldwide have acknowledged the trend toward acceptance of touchscreens as a highly desirable user interface component and have begun to integrate touchscreen functionality into the fundamental design of their products     (Sony VGP-BPL15 battery)      .

Technologies

There are a variety of touchscreen technologies.

Resistive

A resistive touchscreen panel is composed of several layers, the most important of which are two thin, metallic, electrically conductive layers separated by a narrow gap          (Dell Inspiron E1505 battery)        .

When an object, such as a finger, presses down on a point on the panel's outer surface the two metallic layers become connected at that point: the panel then behaves as a pair of voltage dividers with connected outputs. This causes a change in the electrical current, which is registered as a touch event and sent to the controller for processing     (Dell Latitude E6400 battery)        .

Surface acoustic wave

Surface acoustic wave (SAW) technology uses ultrasonic waves that pass over the touchscreen panel. When the panel is touched, a portion of the wave is absorbed. This change in the ultrasonic waves registers the position of the touch event and sends this information to the controller for processing      (HP Pavilion dv6000 Battery)        .

Surface wave touch screen panels can be damaged by outside elements. Contaminants on the surface can also interfere with the functionality of the touchscreen.

Capacitive

Capacitive touchscreen of a mobile phone      (Sony Vaio VGN-FZ31S battery)

A capacitive touchscreen panel consists of an insulator such as glass, coated with a transparent conductor such as indium tin oxide (ITO). As the human body is also a conductor, touching the surface of the screen results in a distortion of the screen's electrostatic field, measurable as a change in capacitance       (Sony VGN-FZ31S battery)          .

Different technologies may be used to determine the location of the touch. The location is then sent to the controller for processing.

Surface capacitance

In this basic technology, only one side of the insulator is coated with a conductive layer. A small voltage is applied to the layer, resulting in a uniform electrostatic field      (Hp pavilion dv6000 battery)      .

When a conductor, such as a human finger, touches the uncoated surface, a capacitor is dynamically formed. The sensor's controller can determine the location of the touch indirectly from the change in the capacitance as measured from the four corners of the panel. As it has no moving parts, it is moderately durable but has limited resolution          (SONY VGN-FZ38M Battery)       ,

is prone to false signals from parasitic capacitive coupling, and needs calibration during manufacture. It is therefore most often used in simple applications such as industrial controls and kiosks       (SONY VGN-FZ31z Battery)     .

Projected capacitance

Projected Capacitive Touch (PCT) technology is a capacitive technology which permits more accurate and flexible operation, by etching the conductive layer     .

An X-Y grid is formed either by etching a single layer to form a grid pattern of electrodes , or by etching two separate    (Sony VGN-FZ31Z Battery)   ,

perpendicular layers of conductive material with parallel lines or tracks to form the grid (comparable to the pixel grid found in many LCD displays).

The greater resolution of PCT allows operation without direct contact, such that the conducting layers can be coated with further protective insulating layers, and operate even under screen protectors, or behind weather and vandal-proof glass    (SONY VGN-FZ31E Battery)     .

Due to the top layer of a PCT being glass, PCT is a more robust solution versus resistive touch technology. Depending on the implementation, an active or passive stylus can be used instead of or in addition to a finger. This is common with point of sale devices that require signature capture        (SONY  VGN-FZ31J Battery)       .

Gloved fingers may or may not be sensed, depending on the implementation and gain settings. Conductive smudges and the like on the panel surface can interfere with the performance. Such conductive smudges come mostly from sticky or sweaty finger tips, especially in high humidity environments       (SONY VGN-FZ31M Battery)       .

Collected dust, which adheres to the screen due to the moisture from fingertips can also be a problem. There are two types of PCT: Self Capacitance and Mutual Capacitance.

Mutual Capacitance

In mutual capacitive sensors, there is a capacitor at every intersection of each row and each column        (SONY VGN-FZ31B Battery) .

A 12-by-16 array, for example, would have 192 independent capacitors. A voltage is applied to the rows or columns. Bringing a finger or conductive stylus close to the surface of the sensor changes the local electrostatic field which reduces the mutual capacitance. The capacitance change at every individual point on the grid can be measured to accurately determine the touch location by measuring the voltage in the other axis        (SONY VGP-BPS13 Battery)        .

Mutual capacitance allows multi-touch operation where multiple fingers, palms or stylus can be accurately tracked at the same time.

Self Capacitance

Self capacitance sensors can have the same X-Y grid as mutual capacitance sensors, but the columns and rows operate independently    (Dell Inspiron 1320 Battery)        .

With self capacitance, the capacitive load of a finger is measured on each column or row electrode by a current meter. This method produces a stronger signal than mutual capacitance, but it is unable to resolve accurately more than one finger, which results in "ghosting", or misplaced location sensing    (Dell Inspiron 1320n Battery)         .

Infrared

An infrared touchscreen uses an array of X-Y infrared LED and photodetector pairs around the edges of the screen to detect a disruption in the pattern of LED beams. These LED beams cross each other in vertical and horizontal patterns. This helps the sensors pick up the exact location of the touch       (Dell Inspiron 1464 Battery)      .

A major benefit of such a system is that it can detect essentially any input including a finger, gloved finger, stylus or pen. It is generally used in outdoor applications and point-of-sale systems which can't rely on a conductor (such as a bare finger) to activate the touchscreen   (Dell Inspiron 1564 Battery)         .

Unlike capacitive touchscreens, infrared touchscreens do not require any patterning on the glass which increases durability and optical clarity of the overall system.

Strain gauge

In a strain gauge configuration, also called force panel technology, the screen is spring-mounted on the four corners and strain gauges are used to determine deflection when the screen is touched       (Dell Inspiron 1764 Battery)  .

This technology has been around since the 1960s, but new advances by Vissumo and F-Origin have made the solution commercially viable. It can also measure the Z-axis and the force of a person's touch. Such screens are typically used in exposed public systems such as ticket machines due to their resistance to vandalism    (Dell Studio 1450 Battery)    .

Optical imaging

This is a relatively modern development in touchscreen technology, in which two or more image sensors are placed around the edges (mostly the corners) of the screen. Infrared back lights are placed in the camera's field of view on the other side of the screen. A touch shows up as a shadow and each pair of cameras can then be triangulated to locate the touch or even measure the size of the touching object (see visual hull)      (Dell Studio 1457 Battery)         .

This technology is growing in popularity, due to its scalability, versatility, and affordability, especially for larger units.

Dispersive signal technology

Introduced in 2002 by 3M, this system uses sensors to detect the mechanical energy in the glass that occurs due to a touch. Complex algorithms then interpret this information and provide the actual location of the touch   (Dell Latitude D610 Battery)         .

The technology claims to be unaffected by dust and other outside elements, including scratches. Since there is no need for additional elements on screen, it also claims to provide excellent optical clarity. Also, since mechanical vibrations are used to detect a touch event, any object can be used to generate these events, including fingers and stylus     (Toshiba NB100 Battery)          .

A downside is that after the initial touch the system cannot detect a motionless finger.

Acoustic pulse recognition

This system, introduced by Tyco International's Elo division in 2006, uses piezoelectric transducers located at various positions around the screen to turn the mechanical energy of a touch (vibration) into an electronic signal       (Toshiba Satellite M65 battery)   .

The screen hardware then uses an algorithm to determine the location of the touch based on the transducer signals. The touchscreen itself is made of ordinary glass, giving it good durability and optical clarity. It is usually able to function with scratches and dust on the screen with good accuracy     (Toshiba Satellite M60 battery)      .

The technology is also well suited to displays that are physically larger. As with the Dispersive Signal Technology system, after the initial touch, a motionless finger cannot be detected. However, for the same reason, the touch recognition is not disrupted by any resting objects       (Dell Latitude D830 Battery)      .

Construction

There are several principal ways to build a touchscreen. The key goals are to recognize one or more fingers touching a display, to interpret the command that this represents, and to communicate the command to the appropriate application.

In the most popular techniques, the capacitive or resistive approach, there are typically four layers     (Dell Studio 1735 Battery)  ;

1. Top polyester layer coated with a transparent metallic conductive coating on the bottom
2. Adhesive spacer
3. Glass layer coated with a transparent metallic conductive coating on the top
4. Adhesive layer on the backside of the glass for mounting      (Dell Latitude D620 Battery)         .

When a user touches the surface, the system records the change in the electrical current that flows through the display.

Dispersive-signal technology which 3M created in 2002, measures the piezoelectric effect — the voltage generated when mechanical force is applied to a material — that occurs chemically when a strengthened glass substrate is touched     (Dell Inspiron Mini 10 Battery)     .

There are two infrared-based approaches. In one, an array of sensors detects a finger touching or almost touching the display, thereby interrupting light beams projected over the screen. In the other, bottom-mounted infrared cameras record screen touches.In each case, the system determines the intended command based on the controls showing on the screen at the time and the location of the touch      (Sony VGN-FW11S Battery)        .

Development

Virtually all of the significant touchscreen technology patents were filed during the 1970s and 1980s and have expired. Touchscreen component manufacturing and product design are no longer encumbered by royalties or legalities with regard to patents and the manufacturing of touchscreen-enabled displays on all kinds of devices is widespread     (Sony VGN-FW11M Battery)       .

The development of multipoint touchscreens facilitated the tracking of more than one finger on the screen, thus operations that require more than one finger are possible. These devices also allow multiple users to interact with the touchscreen simultaneously   (Dell Studio 1555 battery)    .

With the growing acceptance of many kinds of products with an integral touchscreen interface, the marginal cost of touchscreen technology is routinely absorbed into the products that incorporate it and is effectively eliminated. As typically occurs with any technology    (Dell Latitude E5400 Battery)     ,

touchscreen hardware and software has sufficiently matured and been perfected over more than three decades to the point where its reliability is proven. As such, touchscreen displays are found today in airplanes, automobiles, gaming consoles, machine control systems, appliances, and handheld display devices of every kind     (Dell Latitude E4200 Battery)       .

With the influence of the multi-touch enabled iPhone, the touchscreen market for mobile devices is projected to produce US$5 billion in 2009.

The ability to accurately point on the screen itself is also advancing with the emerging graphics tablet/screen hybrids   (Dell Vostro A840 Battery)     .

Ergonomics and usage

Finger stress

An ergonomic problem of touchscreens is their stress on human fingers when used for more than a few minutes at a time, since significant pressure can be required for certain types of touchscreen      (Dell Inspiron 300M Battery)           .

As the touch screen craze continues to grow society is experiencing a lot more finger stress . This can be alleviated for some users with the use of a pen or other device to add leverage and more accurate pointing. The introduction of such items can sometimes be problematic, depending on the desired use (e.g., public kiosks such as A.T.M.s)       (Dell Studio 1737 battery)       .

Also, fine motor control is better achieved with a stylus, because a finger is a rather broad and ambiguous point of contact with the screen itself.

Fingernail as stylus

Pointed nail for easier typing. The concept of using a fingernail trimmed to form a point, to be specifically used as a styluson a writing tablet for communication, appeared in the 1950 science fiction short story Scanners Live in Vain    (Dell Inspiron E1505 battery)      .

These ergonomic issues of direct touch can be bypassed by using a different technique, provided that the user's fingernails are either short or sufficiently long. Rather than pressing with the soft skin of an outstretched fingertip, the finger is curled over, so that the tip of a fingernail can be used instead       (Dell Latitude E6400 battery)      .

The thumb is optionally used to provide support for the finger or for a long fingernail, from underneath. This method does not work on capacitive touch screens.

The fingernail's hard, curved surface contacts the touchscreen at one very small point      (Dell RM791 battery)         .

Therefore, much less finger pressure is needed, much greater precision is possible (approaching that of a stylus, with a little experience), much less skin oil is smeared onto the screen, and the fingernail can be silently moved across the screen with very little resistance , allowing for selecting text, moving windows, or drawing lines      (Dell XPS M2010 battery)     .

The human fingernail consists of keratin which has a hardness and smoothness similar to the tip of a stylus (and so will not typically scratch a touchscreen). Alternately, very short stylus tips are available, which slip right onto the end of a finger; this increases visibility of the contact point with the screen    (Dell XPS M1530 battery)      .

Fingerprints

Touchscreens can suffer from the problem of fingerprints on the display. This can be mitigated by the use of materials with optical coatings designed to reduce the visible effects of fingerprint oils, such as the oleophobic coating used in the iPhone 3G S, or by reducing skin contact by using a fingernail or stylus    (Dell Vostro 1000 battery)        .

Combined with haptics

The user experience with touchscreens without tactile feedback or haptics can be difficult due to latency or other factors. Research from the University of Glasgow Scotland [Brewster, Chohan, and Brown 2007] demonstrates that sample users reduce input errors (20%), increase input speed (20%), and lower their cognitive load (40%) when touchscreens are combined with haptics or tactile feedback,   (Acer Aspire One battery)          .

Gorilla arm

The Jargon File dictionary of hacker slang defined Gorilla Arm as the failure to understand the ergonomics of vertically mounted touch screens for prolonged use. The proposition is that human arm held in an unsupported horizontal position rapidly becomes fatigued and painful, the so-called "gorilla arm"      (Toshiba Satellite P10 Battery)     .

It is often cited as a prima facie example of what not to do in ergonomics. Vertical touchscreens still dominate in applications such as ATMs and data kiosks in which the usage is too brief to be an ergonomic problem.

Discomfort might be caused by previous poor posture and atrophied muscular systems caused by limited physical exercise    (SONY VGN-FZ210CE Battery)   .

Fine Art Painters are also often subject to neck and shoulder pains due to their posture and the repetitiveness of their movements while painting.

Mobile Devices With Touch Displays

Some mobile devices [cell phones, handheld game devices] are Apple iPhone      (Dell Precision M70 Battery)       ,

Apple iPod Touch, Google Android OS Powered Phones, Palm WebOS devices, some of LG [with Verizon stock OS] phones have a touch screen [some of the most popular are the LG enV Touch, LG Dare, LG Voyager], Apple iPod Nano, Apple iPad, UMPCs, and many more       (Toshiba Satellite L305 Battery)      .

Touchpad

A touchpad (also trackpad) is a pointing device consisting of specialized surface that can translate the motion and position of a user's fingers to a relative position on screen. They are a common feature of laptop computers and also used as a substitute for a computer mouse where desk space is scarce     (Toshiba Satellite T4900 Battery)     .

Touchpads vary in size but are rarely made larger than 40 square centimeters (6.3 x 6.3 cm or about 6 inch²). They can also be found on personal digital assistants (PDAs) and some portable media players, such as the iPod using the click wheel.

A touchpad is perhaps the most common kind of tactile sensor     (Toshiba PA3399U-2BRS battery)        .

Operation and function

Touchpads operate in one of several ways, including capacitive sensing and conductance sensing. The most common technology used as of 2010 entails sensing the capacitative virtual ground effect of a finger, or the capacitance between sensors   (Toshiba Satellite A200 Battery)         .

Capacitance-based touchpads will not sense the tip of a pencil or other similar implement. Gloved fingers may also be problematic.

If the computer is powered by an external power supply unit (PSU), the detailed construction of the PSU will influence the virtual ground effect     (Toshiba Satellite 1200 Battery)        ;

a touchpad may work properly with one PSU but be jerky or malfunction with another (this does not imply any electrical risk whatsoever, a delicate capacitative ground, not a contact ground, is at issue). This has been known to cause touchpad problems when a manufacturer's PSU, which will have been designed to work with the touchpad, is replaced by a different type   (Toshiba Satellite M300 Battery)       .

This effect can be checked by touching a metallic part of the computer with the other hand and seeing if operation is restored. In some cases touching the (insulated) power supply with some part of the body, or using the computer on the lap instead of on a desk, while working can restore correct operation    (Dell Latitude XT2 Tablet PC Battery)      .

While touchpads, like touchscreens, by their design are able to sense absolute position, resolution is limited by their size. For common use as a pointer device, the dragging motion of a finger is translated into a finer, relative motion of the cursor on the screen, analogous to the handling of a mouse that is lifted and put back on a surface     (Toshiba Portege 335CT Battery)        .

Hardware buttons equivalent to a standard mouse's left and right buttons are below, above or, to reduce the depth of the pad in compact devices such as netbooks, beside the pad.

On some touchpads and associated device driver software tapping the pad may be interpreted as a click, and a tap followed by a continuous pointing motion (a "click-and-a-half") can be used for dragging         (Dell Vostro A90 Battery)       .

Touchpad drivers can also allow the use of multiple fingers to facilitate the other mouse buttons (commonly two-finger tapping for the center button).

Some touchpads have "hotspots", locations on the touchpad used for functionality beyond a mouse     (Toshiba Satellite P15  Battery) .

For example, on certain touchpads, moving the finger along an edge of the touch pad will act as a scroll wheel, controlling the scrollbar and scrolling the window that has the focus vertically or horizontally. Apple uses two-finger dragging for scrolling on their trackpads      (Toshiba Satellite Pro M10 Battery)      .

Also, some touchpad drivers support tap zones, regions where a tap will execute a function, for example, pausing the media player or launching an application. All of these functions are implemented in the touchpad device driver software, and can be disabled.

Edge motion

Edge motion is a property of a notebook computer's touchpad which lets the user scroll the computer screen without having to move the pointer to ascrollbar      (Toshiba Portege 3110 Battery)          .

Moving the finger along an edge of the touch pad acts as a scroll wheel, scrolling the window that has the focus vertically or horizontally depending on which edge is stroked.

When the scrolling operation is complete, the cursor returns to its original position. This saves the labor of (1) moving the cursor to the scrollbar and (2) moving it back to where it was        (Toshiba Portege R600 Battery)   .

Touchpads in devices

Early Apollo desktop computers were equipped with a touchpad on the right side of the keyboard.

Touchpads are primarily used in self-contained portable laptop computers and do not require a flat surface near the machine  (Toshiba Satellite 1900 Battery)      .

The touchpad is close to the keyboard, and only very short finger movements are required to move the cursor across the display screen; while advantageous, this also makes it possible for a user's thumb to move the mouse cursor accidentally while typing. Touchpad functionality is available for desktop computers in keyboards with built-in touchpads    (Toshiba Portege R200 Battery) .

One-dimensional touchpads are the primary control interface for menu navigation on the currently produced iPod Classic portable music player, where they are referred to as "click wheels" since they only sense motion along one axis which is wrapped around like a wheel      (SONY VAIO VGN-FZ21m Battery)       .

Creative Labs also uses a touchpad for their Zen line of MP3 players, beginning with the Zen Touch. The second-generationMicrosoft Zune product line (the Zune 80/120 and Zune 4/8) uses touch for the Zune Pad.

Apple's PowerBook 500 series was the first laptop to carry such a device, which Apple refers to as a "trackpad"    (SONY VAIO VGN-FZ18m Battery)       .

When introduced in May 1994 it replaced the trackball of previous PowerBook models. Apple's more recent laptops feature trackpads that can sense up to five fingers simultaneously, providing more options for input, such as the ability to bring up the context menu by tapping two fingers    (Dell Vostro A90 Battery)      .

In late 2008 Apple's revisions of the MacBook and MacBook Pro have a different touchpad design with the button incorporated into the tracking surface.

Psion PLC's Psion MC 200/400/600/WORD Series, introduced in 1989        (Dell Vostro A860 Battery)       ,

came with a new mouse-replacing input device similar to a touchpad, although more closely resembling a graphics tablet, as the cursor was positioned by clicking on a specific point on the pad, instead of moving it in the direction of a stroke.

Theory of operation

There are two principal means by which touchpads work          (Dell Vostro 2510 Battery)          .

In the matrix approach, a series of conductors are arranged in an array of parallel lines in two layers, separated by an insulator and crossing each other at right angles to form a grid. A high frequency signal is applied sequentially between pairs in this two-dimensional grid array. The current that passes between the nodes is proportional to the capacitance      (Dell Vostro 1700 Battery) .

When a virtual ground, such as a finger, is placed over one of the intersections between the conductive layer some of the electrical field is shunted to this ground point, resulting in a change in the apparent capacitance at that location. This method received U.S. Patent 5,305,017 awarded to George Gerpheide in April 1994      (Dell Vostro 1400 Battery)        .

The capacitive shunt method, described in an application note by Analog Devices, senses the change in capacitance between a transmitter and receiver that are on opposite sides of the sensor. The transmitter creates an electric field which oscillates at 200-300 kHz        (Dell Vostro 1510 Battery)    .

If a ground point, such as the finger, is placed between the transmitter and receiver, some of the field lines are shunted away, decreasing the apparent capacitance     (HP Pavilion DV7 Battery)         .