Biclique cryptanalysis on the full crypton-256 and mCrypton-128

Biclique cryptanalysis is an attack which reduces the computational complexity by finding a biclique which is a kind of bipartite graph. we show a single-key full-round attack of the crypton-256 and mcrypton-128 by using biclique cryptanalysis. in this paper,4-round bicliques are constructed for crypton-256 and mcrypton-128. and these bicliques are used to recover master key for the full rounds of crypton-256 and mcrypton-128 with the computational complexities of 2253.78 and 2126.5,respectively. this is the first known single-key full-round attack on the crypton-256. and our result on the mcrypton-128 has superiority over known result of biclique cryptanalysis on the mcrypton-128 which constructs 3-round bicliques in terms of computational time complexity. © 2014 junghwan song et al.