Integral and Impossible Differential Cryptanalysis of RC6
The block cipher RC6 is one of the finalists of the five candidates of AES for its security, simplicity and easy soft-hardware implementation. In view of its importance, the resistance of RC6 against integral cryptanalysis and impossible differential cryptanalysis is evaluated in this paper. The result shows that the complexities of both integral attack on RC6 reduced to 4 rounds and impossible differential attack on RC6 reduced to 5 rounds are lower than exhaustive search. Meanwhile, it is demonstrated that RC6 with more rounds is immune to the two kinds of cryptanalysis since the data-dependent cycle increases the diffusion immensely.