Cryptomeria cipher
The Feistel function of the Cryptomeria cipher.  | |
| General | |
|---|---|
| Designers | 4C Entity | 
| First published | 2003 | 
| Derived from | DES | 
| Related to | CSS | 
| Cipher detail | |
| Key sizes | 56 bits | 
| Block sizes | 64 bits | 
| Structure | Feistel network | 
| Rounds | 10 | 
| Best public cryptanalysis | |
| A boomerang attack breaks all 10 rounds in 248 time with known S-box, or 253.5 with an unknown S-box, using 244 adaptively chosen plaintexts/ciphertexts. | |
The Cryptomeria cipher, also called C2, is a proprietary block cipher defined and licensed by the 4C Entity. It is the successor to CSS algorithm (used for DVD-Video) and was designed for the CPRM/CPPM digital rights management scheme which are used by DRM-restricted Secure Digital cards and DVD-Audio discs.