CSS (DVD-Video):
Contents Scrambling System is the copy protection mechanism
for DVD-Video. It uses a weak 40-bit proprietary encryption
algorithm instead of a stronger public-key algorithm.
It was designed to comply with strict US government
crypto-export regulations. Even if the encryption were
stronger--and DVD hardware players that plug into televisions
and software players downloaded to a PC--all have their
own unique key that unlocks the encryption key on the
DVD. Each DVD has 400 copies of the same decryption
key, each encrypted with every unlock code needed for
each player. If one unlock key is compromised, every
DVD can be decrypted
Cryptanalysis
of Contents Scrambling System - CSS is a scrambling
system used in the distribution for movies on DVD. Its
main purpose is to prevent the unauthorized duplication
of disc contents.
"Reading
Between the Lines: Lessons from the SDMI Challenge",
analysis of the defeated SDMI audio-protection system.
The Verance Watermark, is currently used for DVD-Audio.
We should expect to see some code soon to demonstrate
the removal of watermarks from the audio tracks on
the DVD-Audio discs.