A New Approach to $chi^2$ Cryptanalysis of Block Ciphers KU Leuven
The main contribution of this paper is a new approach to χ 2 analyses of block ciphers in which plaintexts are chosen in a manner similar to that in a square/saturation attack. The consequence is a faster detection of χ 2 correlation when compared to conventional χ 2 cryptanalysis. Using this technique we (i) improve the previously best-known χ 2 attacks on 2- and 4-round RC6, and (ii) mount the first attacks on the MRC6 and ERC6 block ciphers. ...