SOME THEORETICAL ASPECTS OF DIFFERENTIAL CRYPTANALYSIS OF THE ITERATEDBLOCK CIPHERS WITH ADDITIVE ROUND KEY | Prikladnaya Diskretnaya Matematika - Applied Discrete Mathematics. 2008. № 1(1).

A common method is formulated for differential cryptanalysis of anyiterated block cipher with additive round key. For a r-round cipher, the method uses its (r-1)-round characteristic and an algorithmfor solving the system of polynomial equations over a finite field describing for the rth round the dependencies of itsknown outputs on its input differences known with a nonzero probability and on its unknown inputs and round key elements. Beforethe method is stated necessary notions are introduced and basic propositions are given concerning the functions defined onfinite abelian groups, iterated block ciphers, their round functions, additive round keys, differential characteristics, round systemof equations over a finite field, and so on. All the notions and assertions are illustrated on DES