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.