# M2 = GF(2^8) * 2 multiplication table
    # for each column i :

    s0 = state[(i<<3) + 0]
    s1 = state[(i<<3) + 1]
    s2 = state[(i<<3) + 2]
    s3 = state[(i<<3) + 3]
    s4 = state[(i<<3) + 4]
    s5 = state[(i<<3) + 5]
    s6 = state[(i<<3) + 6]
    s7 = state[(i<<3) + 7]

    h = s7 ^ s6 ^ s5 ^ s4 ^ s3 ^ s2 ^ s1 ^ s0
    xh = M2[h] ^ h

    state[(i<<3) + 0] ^= M2[M2[s7 ^ s6 ^ s4 ^ s3] ^ s6 ^ s4 ^ s3] ^ xh ^ s1 ^ s3
    state[(i<<3) + 1] ^= M2[M2[s0 ^ s7 ^ s5 ^ s4] ^ s7 ^ s5 ^ s4] ^ xh ^ s2 ^ s4
    state[(i<<3) + 2] ^= M2[M2[s1 ^ s0 ^ s6 ^ s5] ^ s0 ^ s6 ^ s5] ^ xh ^ s3 ^ s5
    state[(i<<3) + 3] ^= M2[M2[s2 ^ s1 ^ s7 ^ s6] ^ s1 ^ s7 ^ s6] ^ xh ^ s4 ^ s6
    state[(i<<3) + 4] ^= M2[M2[s3 ^ s2 ^ s0 ^ s7] ^ s2 ^ s0 ^ s7] ^ xh ^ s5 ^ s7
    state[(i<<3) + 5] ^= M2[M2[s4 ^ s3 ^ s1 ^ s0] ^ s3 ^ s1 ^ s0] ^ xh ^ s6 ^ s0
    state[(i<<3) + 6] ^= M2[M2[s5 ^ s4 ^ s2 ^ s1] ^ s4 ^ s2 ^ s1] ^ xh ^ s7 ^ s1
    state[(i<<3) + 7] ^= M2[M2[s6 ^ s5 ^ s3 ^ s2] ^ s5 ^ s3 ^ s2] ^ xh ^ s0 ^ s2