Conference paper · Book chapter
Cryptanalysis of C2
In
Advances in Cryptology - Crypto 2009
—
2009, pp. 250-266
Abstract
We present several attacks on the block cipher C2, which is used for encrypting DVD Audio discs and Secure Digital cards. C2 has a 56 bit key and a secret 8 to 8 bit S-box. We show that if the attacker is allowed to choose the key, the S-box can be recovered in 2^24 C2 encryptions. Attacking the 56 bit key for a known S-box can be done in complexity 2^48.
Finally, a C2 implementation with a 8 to 8 bit secret S-box (equivalent to 2048 secret bits) and a 56 bit secret key can be attacked in 2^53.5 C2 encryptions on average.
| Language: | English |
|---|---|
| Publisher: | Springer |
| Year: | 2009 |
| Edition: | 1st |
| Pages: | 250-266 |
| Proceedings: | CRYPTO |
| Journal subtitle: | 29th Annual International Cryptology Conference |
| ISBN: | 3642033555 , 3642033563 , 9783642033551 and 9783642033568 |
| ISSN: | 16113349 and 03029743 |
| Types: | Conference paper and Book chapter |
| DOI: | 10.1007/978-3-642-03356-8 |
| ORCIDs: | Knudsen, Lars Ramkilde |
