GOST R 34.12-2015: Block Cipher "Magma"
In addition to a new cipher with a block length of n=128 bits (referred to as "Kuznyechik" and described in RFC 7801), Russian Federal standard GOST R 34.12-2015 includes an updated version of the block cipher with a block length of n=64 bits and key length of k=256 bits, which is also referred to as "Magma". The algorithm is an updated version of an older block cipher with a block length of n=64 bits described in GOST 28147-89 (RFC 5830). This document is intended to be a source of information about the updated version of the 64-bit cipher. It may facilitate the use of the block cipher in Internet applications by providing information for developers and users of the GOST 64-bit cipher with the revised version of the cipher for encryption and decryption.