CSKH-01.2020. Abstract—The cryptographic algorithms Kuznyechik and Magma since 2015 are block cipher standardized in the Russian Federation, formally called GOST R 34.12-2015. Both use fixed functions as a priori selected and differ on the structure, the block length and the bit-level of the processed blocks. In the present paper, we provide a dynamic variant of Kuznyechik and Magma where some of their functions are randomly generated and dependent on pseudorandom sequences.

CSKH-01.2020. Abstract—The cryptographic algorithm AES (Advanced Encryption Standard) works with the transformations SubBytes, ShiftRows, MixColumns and AddRoundKey, all of them fixed and selected a priori. In this paper, we will show dynamic variants of AES, where the new transformations are RandomSubBytes, RandomShiftRows, RandomMixColumns and RandomAffineTransfKey.

 CSKH- 02.2018 - (Abstract) - Random Sequences and random numbers play a very important role in cryptography. In symmetric cryptography primitives, a secret key is the most important component to ensure their security. While cryptographic protocols or digital signature schemes are also strongly dependent on random values. In addition, one of the criteria for evaluating security for cryptographic primitives such as block cipher, hash function... is to evaluate the output randomness. Therefore, the assessment of randomness according to statistical tests is really important for measuring the security of cryptographic algorithms. In this paper, we present some research results on randomness tests based on the length of runs proposed by A. Doğanaksoy et al in 2015. First, we show that some probability values for tests based on lengths 1 and 2 are inaccurate and suggest editing. Secondly, we have given and demonstrated for the general case the runs of any length k. Finally, we built a randomness testing tool and applied evaluations to true random sources.