Key2Audio
Encyclopedia
key2audio is a copy restriction system for Audio CD
s, developed by Sony DADC
. The system gained notoriety after it was discovered that one can effectively disable the system by tracing the outer edge of a CD with a felt-tip marker.
The system works by applying a bogus data track onto the disc during glass master manufacturing. Since computers are designed to read data before music, this prevents playback on a PC and thereby prevents ripping
as well as ordinary listening using a computer. CD players ignore any non-audio tracks on a disc, and can therefore play the CD unimpeded - Enhanced CD
s also take advantage of this factor.
Currently there are two major versions of the key2Audio protection: the original key2Audio, and key2AudioXS.
" logo. As with any passive DRM technology some players are unable to play the non-standard disc.
Since optical computer CD/DVD drives are also capable of reading Red Book audio CDs, a lot of player manufacturers use these same CD/DVD ROM drives instead of specialized Audio CD / Video DVD only drives in order to reduce costs.
DVD players and car stereo systems seem to have most problems with incompatibilities of key2Audio protected CDs.
A protected CD still achieves a maximum recording time of 77 minutes and supports full ISRC, UPC
and CD-Text
capabilities.
Early versions of this copy protection were infamous for being easily circumvented with a marker pen
, by drawing a circle on the rim of the visible edge of audio data.http://www.usatoday.com/money/tech/2002-05-20-copyproof-cd.htm
written on the disc. Two of them contain small data tracks, and one contains the audio tracks. The regular CD players pick the audio tracks outright, while the computer CD and DVD players get confused by the corrupted TOC information. CD players and drives that do not support multisession discs are immune against this confusion.
It can be worked around by e.g. CloneCD
or Exact Audio Copy
.
The new version of this protection allows the listener the right to play the CD on a PC, and allows controlled burning the audio to CD. This solution allows consumers a limited amount of private copies. The record labels can individually define the burn count. These copies are then also fully protected and offer the same efficiency and compatibility as the original disc.
The audio sessions are being encoded to Windows Media Audio
DRM
-protected files, so that some portable devices are supported and online distribution prevented.
Furthermore, with key2audioXS the user can now pick and send audio tracks via email. With a usability period defined by the record label, users can share music, facilitating promotion activities for labels.
Additionally, some discs feature "n-CD", which lets the user access bonus features such as videos, ringtones, lotteries and the like. The original n-CD is a unique key reserved for just their owners.
For this purpose, the user interface for key2Audio on PC allows for navigation and includes a copying and burning tool, as well as additional content such as bonus pictures and lyrics.
The audio part can hold up to 75 minutes.
Red Book (audio CD standard)
Red Book is the standard for audio CDs . It is named after one of the Rainbow Books, a series of books that contain the technical specifications for all CD and CD-ROM formats.The first edition of the Red Book was released in 1980 by Philips and Sony; it was adopted by the Digital Audio Disc...
s, developed by Sony DADC
Sony
, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....
. The system gained notoriety after it was discovered that one can effectively disable the system by tracing the outer edge of a CD with a felt-tip marker.
The system works by applying a bogus data track onto the disc during glass master manufacturing. Since computers are designed to read data before music, this prevents playback on a PC and thereby prevents ripping
Ripping
Ripping is the process of copying audio or video content to a hard disk, typically from removable media. The word is used to refer to all forms of media. Despite the name, neither the media nor the data is damaged after extraction....
as well as ordinary listening using a computer. CD players ignore any non-audio tracks on a disc, and can therefore play the CD unimpeded - Enhanced CD
Enhanced CD
Enhanced CD, also known as CD Extra and CD Plus, is a certification mark of the Recording Industry Association of America for various technologies that combine audio and computer data for use in both Compact Disc and CD-ROM players....
s also take advantage of this factor.
Currently there are two major versions of the key2Audio protection: the original key2Audio, and key2AudioXS.
key2Audio
key2audio products are highly compatible because the audio session is not modified. Since additional data sessions are used, the CD is not Red Book compliant and should not use the "Compact DiscCompact Disc
The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...
" logo. As with any passive DRM technology some players are unable to play the non-standard disc.
Since optical computer CD/DVD drives are also capable of reading Red Book audio CDs, a lot of player manufacturers use these same CD/DVD ROM drives instead of specialized Audio CD / Video DVD only drives in order to reduce costs.
DVD players and car stereo systems seem to have most problems with incompatibilities of key2Audio protected CDs.
A protected CD still achieves a maximum recording time of 77 minutes and supports full ISRC, UPC
Universal Product Code
The Universal Product Code is a barcode symbology , that is widely used in North America, and in countries including the UK, Australia, and New Zealand for tracking trade items in stores. Its most common form, the UPC-A, consists of 12 numerical digits, which are uniquely assigned to each trade item...
and CD-Text
CD-Text
CD-Text is an extension of the Red Book Compact Disc specifications standard for audio CDs. It allows for storage of additional information on a standards-compliant audio CD...
capabilities.
Early versions of this copy protection were infamous for being easily circumvented with a marker pen
Marker pen
thumb|MarkerA marker pen, marking pen, felt-tip pen, flow or marker, is a pen which has its own ink-source, and usually a tip made of a porous, pressed fibres; such as felt or nylon.-Permanent marker:...
, by drawing a circle on the rim of the visible edge of audio data.http://www.usatoday.com/money/tech/2002-05-20-copyproof-cd.htm
Technical background
It appears that key2Audio protected disc TOC contains three sessionsSession (CD)
Data on a compact disc or a DVD are laid out in sessions. Each session consists of a lead-in, containing the session's table of contents, the program area in which the individual tracks are located, and the lead-out....
written on the disc. Two of them contain small data tracks, and one contains the audio tracks. The regular CD players pick the audio tracks outright, while the computer CD and DVD players get confused by the corrupted TOC information. CD players and drives that do not support multisession discs are immune against this confusion.
It can be worked around by e.g. CloneCD
CloneCD
CloneCD is proprietary optical disc authoring software that makes exact, 1:1 copies of music and data CDs and DVDs, regardless of any Digital Rights Management restrictions. It was originally written by Oliver Kastl and offered by Swiss company Elaborate Bytes, but due to changes in European...
or Exact Audio Copy
Exact Audio Copy
Exact Audio Copy is a proprietary CD ripping program for Microsoft Windows. It has also been tested to work under newer versions of Wine on Linux...
.
key2AudioXS
key2audioXS combines a PC playback and a clone-proof Multimedia session for CD-Extra and Web Links.The new version of this protection allows the listener the right to play the CD on a PC, and allows controlled burning the audio to CD. This solution allows consumers a limited amount of private copies. The record labels can individually define the burn count. These copies are then also fully protected and offer the same efficiency and compatibility as the original disc.
The audio sessions are being encoded to Windows Media Audio
Windows Media Audio
Windows Media Audio is an audio data compression technology developed by Microsoft. The name can be used to refer to its audio file format or its audio codecs. It is a proprietary technology that forms part of the Windows Media framework. WMA consists of four distinct codecs...
DRM
Digital rights management
Digital rights management is a class of access control technologies that are used by hardware manufacturers, publishers, copyright holders and individuals with the intent to limit the use of digital content and devices after sale. DRM is any technology that inhibits uses of digital content that...
-protected files, so that some portable devices are supported and online distribution prevented.
Furthermore, with key2audioXS the user can now pick and send audio tracks via email. With a usability period defined by the record label, users can share music, facilitating promotion activities for labels.
Additionally, some discs feature "n-CD", which lets the user access bonus features such as videos, ringtones, lotteries and the like. The original n-CD is a unique key reserved for just their owners.
For this purpose, the user interface for key2Audio on PC allows for navigation and includes a copying and burning tool, as well as additional content such as bonus pictures and lyrics.
The audio part can hold up to 75 minutes.