In the paper created a new encryption algorithms GOST28147–89–IDEA8–4 and GOST28147–89–RFWKIDEA8– 4 based on networks IDEA8–4 and RFWKIDEA8–4, with the use the round function of the encryption algorithm GOST 28147–89. The block length of created block encryption algorithm is 256 bits, the number of rounds is 8, 12 and 16.