Differential Cryptanalysis
Henri Gilbert, Jérémy Jean · 2023
This chapter provides some general background on the cryptanalysis of iterated block ciphers and introduces the notion of distinguisher that is instrumental in most known classes of attacks on such ciphers. It presents the main notions encountered in differential cryptanalysis, for example, the notions of differential characteristic and differential, using Biham and Shamir's seminal attack against up to 15 Data Encryption Standard rounds as our main guiding thread. The chapter outlines a few examples of the possible refinements or extensions of differential cryptanalysis, in particular the differential effect and the case of truncated differential characteristics. It summarizes some of the strategies followed by block cipher designers to achieve resistance against differential cryptanalysis, in particular the wide trail strategy that represents the main design rationale behind the Advanced Encryption Standard. The chapter concludes by providing a few notes and references to some notable results related to differential cryptanalysis.