Translation of Algorithmic Descriptions of Discrete Functions to SAT with Applications to Cryptanalysis Problems

In the present paper we describe the technology for translating algorithmic descriptions of discrete functions to SAT. The proposed methods and algorithms of translation are aimed at application to the problems of SAT-based cryptanalysis. In the theoretical part of the paper we justify the main principles of general reduction to SAT for discrete functions from a class containing the majority of functions employed in cryptography. Based on these principles we describe the Transalg software system, developed with SAT-based cryptanalysis specifics in mind. We show the results of applications of Transalg to construction of a number of attacks on various cryptographic functions. Some of the corresponding attacks are state of the art. In the paper we also present the vast experimental data, obtained using the SAT-solvers that took first places at the SAT-competitions in the recent several years.