University of Ljubljana
The two most established cryptanalytic methods against block ciphers are linear cryptanalysis and differential cryptanalysis. These attacks are statistical in nature, in which the attacker attempts to construct probabilistic patterns through as many rounds of the cipher as possible, in order to distinguish the cipher from a random permutation, and ultimately recover the key. In this paper the authors propose a new cryptanalytic method against block ciphers, which combines both algebraic and statistical techniques. More specifically, they show how to use algebraic relations arising from differential characteristics to speed up and improve key-recovery differential attacks against block ciphers.