Cobra-F64a and Cobra-F64b, designed for firmware-oriented applications, are 64-bit Data-dependent Permutation based block ciphers with 128 key bits, which consist of 16 and 20 rounds, respectively. In this paper, we investigate their security against related-key attacks. Our investigation shows that the full 16-round Cobra-F64a can be broken by our related-key rectangle attack and that the full 20-round Cobra-F64b can be broken by our related-key differential attack.
|Title of host publication||Security and Cryptography for Networks (5th International Conference, SCN 2006, Maiori, Italy, September 6-8, 2006, Proceedings)|
|Editors||R. De Prisco, M. Yung|
|Place of Publication||Berlin|
|Publication status||Published - 2006|
|Name||Lecture Notes in Computer Science|