Shift key breaks latest CD anti-rip tech – grad student

A Princeton PhD student has published a paper detailing the music industry's latest CD copy protection scheme - and how the technique can be bypassed by simply holding down the host computer's Shift key when a 'protected' CD is inserted.

The copy-protection mechanism in question is SunnComm's MediaMax CD3 system. Launched in September, the company claimed its technology had passed strict testing to Recording Industry Ass. of America (RIAA) copy-protection standards with "flying colours".

The "comprehensive test procedures" - SunnComm's words - were performed by "world-renowned" Professional Multimedia Test Centre (PMTC), based in Belgium. PMTC Division Manager Frans Pender is quoted by SunnComm as saying MediaMax C3 offered "an incredible level of security for the music".

However, Princeton Computer Science Department student Alex Halderman's own analysis concludes MediaMax C3 is "irreparably flawed" thanks to the "weakness of its design". It is, he reckons, "unlikely to cause any significant reduction in copying".

He adds: "In practice, many users who try to copy the disc will succeed without even noticing that it's protected, and all others can bypass the protections with as little as a single keystroke."

Halderman probed SunnComm's technology using an off-the-shelf CD from music label BMG. He found that when the disc was first inserted, it auto-installs a device driver that subsequently interferes with attempts to copying the songs on the CD. The disc contains versions of its songs in DRM-protected WMA format, to allows computer users to listen to the tracks freely and to download the songs to a Microsoft DRM-enabled portable music player.

MediaMax C3 uses Windows' Auto-run feature to install the device driver, says Halderman. By holding down the Shift key, Auto-run can be temporarily disabled, preventing the driver from being installed, and allowing the user to access the otherwise unprotected - and uninterefered with - standard AIFF tracks.

Those tracks are unprotected in order to allow the CD to be played on video game systems and DVD players. Other copy-protection mechanisms, which add errors to the music code on the CD, for example, have foundered because they proved problematic when used on these 'legitimate' playback systems. Ditto their inability to work on Macs. Halderman rightly acknowledges SunnComm's attempt to remove these restrictions, though he points out that the company's technology still leaves Linux users in the dark.

"The driver examines each CD placed in the machine, and when it recognizes the protected title, it actively interferes with read operations on the audio content," writes Halderman. The CD contains drivers for Windows 98/ME/2000/XP and Mac OS X.

Halderman is no mere dilettante in matters of copy protection. He studies under Princeton Professor Ed Felten, who lead the team that successfully took up the challenge to crack the ill-fated SDMI encryption system, and was threatened by the RIAA with a Digital Millennium Copyright Act infringement suit for his trouble.

Halderman has himself published a number of papers on the topic of copy-protection mechanisms.

SunnComm admits its technololgy isn't perfect: "MediaMax CD3 is not a 'holy grail' solution expected to end illicit file duplication and unlicensed sharing," said COO William H Whitemore at the launch. "However, what we expect it will do is create an effective structure on the CD itself that encourages legal and licensed copying activities.

"A determined 'digital shoplifter', like any thief, can always find ways to steal," he added. "However, when record companies employ MediaMax, they create a legal way for music lovers to copy and share the music they purchase."

That said, we're not sure that he had "a way to steal" as simple as the one revealed by Halderman.

We asked SunnComm for comment, but the company did not return our calls. PMTC's Pender was similarly unavailable. ®