Expand description
CSS cipher implementation based on the Stevenson 1999 analysis.
The CSS cipher uses two table-driven feedback circuits:
- LFSR1: 9-bit state (two halves), driven by TAB2/TAB3
- LFSR0: 32-bit state, driven by a feedback polynomial through TAB4
The keystream is the bytewise sum (with carry) of both LFSR outputs. Content descrambling XORs this keystream with the encrypted sector data.
Algorithm: Frank A. Stevenson’s divide-and-conquer attack (1999). Tables: CSS specification constants.
Functions§
- descramble_
sector - Descramble a CSS-encrypted DVD sector in place.