Evaluating New Copy-Prevention Techniques For Audio CDs John A. Halderman 2002 ACM Workshop on Digital Rights Management (DRM 2002) Available at (March 2003) Simon Fisher

Summary The article gives a brief discussion of copy-prevention and copyright issues Outlines and conducts an experiment with 3 forms of copy-protection –Are they effective? –How do they work? –Can they be defeated? Concludes that the techniques are harmful to legitimate users

The Experiment Three CD’s with different forms of copy- protection –The study was “constrained by the small number of recordings known to emply copy-prevention techniques” Various combinations of hardware and software –Operating Systems –CD Drives –Playing / Copying / Ripping utilities

Are they effective? Results showed the techniques were effective –Of 75 trials, only 13 were successful –Successful meaning that all tracks “played, extracted, or copied correctly”.

How do they work? By exploiting weaknesses in hardware and software –Table of Contents errors Incorrect track type / times Non-existent tracks –Multiple Session Bugs By having fictitious or invalid extra sessions, can confuse software and/or hardware

Can they be defeated? Yes, by making the software and hardware used more robust to errors In fact they already have –“A quick search on the Kazaa and Gnutella file trading networks in May 2002 revealed copies of nearly every track freely available for downloading.” Once hardware becomes robust enough, software fixes will be too rapid for these kinds of techniques to be feasible

Conclusions Halderman concludes that as these techniques are so easily circumvented, their only effect is to irritate legitimate owners And may encourage people to avoid copy- protected CD’s and/or turn to piracy “These ill-conceived schemes will amount to little more than a temporary speed bump for copyright infringement and promise to further alienate [legitimate] customers from the record industry.”

Critical Comments Confusion over ‘effectiveness’ –Halderman says the copy-prevention techniques are effective, but then also states they can be easily circumvented. –He never really defines what kind of people the copy-prevention techniques are effective against. Advanced users who can use more sophisticated software Or people who may not have much experience with computers.

Critical Comments I don’t think the techniques studied are as ineffective as the article claims –Many owners of these copy-protected CD’s may not know how to use the software that can bypass the protection –Nearly all of the tests under Windows failed –Hence the techniques are at least partially successful

Appreciative Comments Haldermans point about copyright lifetimes –Copyright provides a limited monopoly as an incentive for the authors’ time and effort –But only for a limited period of time –If these copy-prevention techniques worked, they would essentially create a permanent copyright

Question The copy-prevention techniques studied were circumvented soon after they were released But it may require a certain degree of expertise in order to bypass them How successful would you say these techniques were, in terms of slowing or preventing illegal distribution?