Digital music protection system cracked

A team of US researchers claims to have successfully defeated key technologies designed to protect copyrighted music.

Researchers from Princeton University, Rice University and Xerox's Palo Alto Research Centre said they have broken all four 'watermark' technologies developed to prevent computer users from listening to illegally copied music. Watermarking allows serial numbers to be embedded in music files and can notify so-called secure players when music is unlawfully copied.

The experiment was in response to a challenge set by the Secure Digital Music Initiative (SDMI) to test four different watermark technologies. The SDMI is a music industry alliance developing a standard for the secure distribution of online music.

The researchers cracked the codes by analysing a song and producing a special filter to erase the watermark. The song was then sent to an SDMI program to determine whether the modified file was accepted, rejected or deemed invalid.

The researchers rendered the watermarks undetectable without significantly degrading the audio quality of the samples and passed the test. They said that SDMI's email server confirmed the success of the experiment.

"I believe all four of the [watermark] schemes would have been cracked by pirates if they had been deployed," said Edward Felton, an associate professor of computer science at Princeton.

The researchers explained that it was not their intention to engage in tactics such as tricking the industry into choosing a flawed system. "Our goal is simply to analyse security systems and share our results openly," they said.

SDMI officials were not immediately available for comment.