A music CD designed to be unplayable in a computer鈥檚 CD-ROM drive has been distributed in the UK 鈥� the aim is to confound those who pirate music on the internet.
Promotional copies of Michael Jackson鈥檚 forthcoming single 鈥淵ou Rock My World鈥� features a copy-prevention mechanism called key2audio. This causes a computer鈥檚 CD-ROM drive to incorrectly interpret the stored data.
A Sony spokesman told New 杏吧原创: 鈥淭here are no plans currently to use similar technology on commercial releases of this record.鈥� The copy protection on the promotional CD is designed to stop the single leaking onto the internet prior to its official release, he says. This has happened before with entire albums from other artists.
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However, some observers believe that Sony鈥檚 action is just one part of a far-reaching strategy designed to stop listeners making digital copies of the music stored on CDs. They fear this will stop them making copies for their personal use.
鈥淚t鈥檚 clear that they now are using copy protection with vigour,鈥� says Julian Midgley of the UK-based Campaign for Digital Rights. He says that enforced copy protection mechanisms will restrict accepted activity, such as copying to mini-disc and MP3 players. 鈥淭he companies that are selling MP3 players are expecting people to do this,鈥� he says.
Error correction
Key2audio alters an audio CD during master copying to make it incompatible with CD-ROM, CD-R and CD-RW drives. A computer鈥檚 CD-ROM makes use of a 鈥渢able of contents鈥� included on software CD鈥檚 to help with error correction. It is possible to write to this area on an audio CD so that the CD-ROM misinterprets the data and it refuses to play.
Sony says that key2audio is just one of several copy protection techniques it is looking at. More subtle copy protection systems have reportedly featured already on CDs commercially released by Sony and other companies. These are designed to play in CD-ROM drives but prevent music being copied to a computer鈥檚 hard drive.
In these systems special errors are added to the data on an audio CD. Stand-alone CD players and CD-ROMs will correct automatically when playing music. But when the data is copied to a computer鈥檚 hard drive, these errors are included and cause irrevocable damage.
The potential problem is that these CDs may not play on some CD players and may deteriorate more quickly. 鈥淭heir life will be shorter,鈥� says Midgley. 鈥淭he result will be that interference appears more quickly.鈥�
Midgley also points out that only one computer programmer needs to upload a music file to the net for a copying spree to start. And the chances of at least one programmer breaking a copyright protection system is high, he says.
