What is "kupyna"

Kupyna is a cryptographic hash function defined in the Ukrainian national standard DSTU 7564:2014. It was created to replace an obsolete GOST hash function defined in the old standard GOST 34.11-95, similar to Streebog hash function standardized in Russia.

In addition to the hash function, the standard also describes message authentication code generation using Kupyna with digest sizes 256, 384 and 512 bits.