An anonymous security researcher working under the pseudonym "Beale Screamer" reverse engineered the Microsoft Digital Rights Management subsystem and, by October 20th, the results were available on cryptome.org. As part of the reverse engineering effort Screamer found an unpublished block cipher, which he dubbed MultiSwap, being used as part of DRM. Screamer did not need to break the MultiSwap cipher to break DRM, but we thought it would be a fun excercise, and summarize the results of our investigation below.. . .
An anonymous security researcher working under the pseudonym "Beale Screamer" reverse engineered the Microsoft Digital Rights Management subsystem and, by October 20th, the results were available on cryptome.org. As part of the reverse engineering effort Screamer found an unpublished block cipher, which he dubbed MultiSwap, being used as part of DRM. Screamer did not need to break the MultiSwap cipher to break DRM, but we thought it would be a fun excercise, and summarize the results of our investigation below.

The attacks described here show weaknesses in the MultiSwap encryption scheme, and could potentially contribute to an attack on DRM. However, the attack on DRM described by Beale Screamer would be much more practical, so we feel that these weaknesses in MultiSwap do not pose a significant threat to DRM at this time.

We present these results to further the science of computer security, not to promote rampant copying of copyrighted music.

The link for this article located at Nikita Borisov, Monica Chew, Rob Johnson, and David Wagner is no longer available.