It seems that an enterprising hacker has busted Amazon's Kindle for PC DRM.
The hacker, going by the name i♥cabbages, has released an app called Unswindle that decrypts Kindle content and transforms them into Mobi format.
The hacker seems to have some admiration for Amazon's DRM implementation on the PC:
The Kindle proper and Kindle for iPhone/iPod app both use a single "device" encryption key for all DRMed content. K4PC uses the same encryption algorithms, but ups the ante with a per-book session key for the actual en/decryption. And they seem to have done a reasonable job on the obfuscation. Way to go Amazon! It's good enough that I got bored unwinding it all and just got lazy with the Windows debugging APIs instead.
It's been possible to decrypt some Amazon Kindle content for some time using a tool called MobiDeDRM, but this is the first time that it's been possible to decrypt Kindle content on the PC. Given that even hardcore DRM such as that implemented on Blu-ray discs was busted, the chances to Amazon's DRM holding out for long was negligible.
Note: I say that it's possible to decrypt some files as opposed to all files because there's no way to decrypt "Topaz" files which contain embedded fonts.
Big business versus the lone hacker is a cat and mouse game. I guess that either Amazon's lawyers or programmers will be working over the Holidays, depending on which counterattack the book giant takes.