Fast Implementation and Cryptanalysis of GOST R 34.12-2015 Block Ciphers

The new cryptographic standard GOST R 34.12-2015 "Information technology. Cryptographic Data Security. Block ciphers." [7] came into force on January 1st, 2016. The standard contains two encryption algorithms. One of those is a former standard encryption algorithm GOST 29147-89 (also known as simply GOST) with fixed S-boxes. This algorithm is denoted as Magma in the new standard. The second algorithm is a new symmetric block cipher based on SP-network, which is denoted as Kuznyechik (also transliterated as "Kuznechik"). Nowadays, a lot of attention is paid to the issues of quality of the new cipher, namely its cryptographic strength, performance, portability, implementation, etc. In this paper we are offering to consider the possibility to use parallel computations based on MPI and NVIDIA CUDA technologies for cryptanalysis of Magma and Kuznyechik. We choose slide attack for the implementation. The slide attack is applicable to Magma and Kuznyechik ciphers only with significant weakening modifications to their original descriptions. However, research on applicability of parallel implementation of cryptanalysis is important, because the parallel approach can be applied to other more efficient methods of cryptanalysis. The proposed parallel algorithms implemented for two different technologies demonstrate close to linear growth of analysis speed with the increase of involved processor cores. Also we propose a fast implementation of Kuznyechik data encryption based on precomputed tables.