Gradient Cryptanalysis of Block Cipher CHAM 64/128

摘要

round function evaluations. Theoretical extrapolation of the suggested attack shows that the key can be completely determined with probability 0.01 after 57 rounds. The recommended number of rounds for CHAM 64/128 is 80. According to the cipher designers, the most successful attack has been a related-key boomerang attack which is effective on 56 rounds.