How do I parallelize this?

gistfile1.txt

    for (round = 1; round <= 9; round++) {
        temp.x =
            key[round].x
            ^ Te0[(ciphertext.x >> 24) & 0xFF]
            ^ Te1[(ciphertext.y >> 16) & 0xFF]
            ^ Te2[(ciphertext.z >>  8) & 0xFF]
            ^ Te3[(ciphertext.w >>  0) & 0xFF];
        temp.y =
            key[round].y
            ^ Te0[(ciphertext.y >> 24) & 0xFF]
            ^ Te1[(ciphertext.z >> 16) & 0xFF]
            ^ Te2[(ciphertext.w >>  8) & 0xFF]
            ^ Te3[(ciphertext.x >>  0) & 0xFF];
        temp.z =
            key[round].z
            ^ Te0[(ciphertext.z >> 24) & 0xFF]
            ^ Te1[(ciphertext.w >> 16) & 0xFF]
            ^ Te2[(ciphertext.x >>  8) & 0xFF]
            ^ Te3[(ciphertext.y >>  0) & 0xFF];
        temp.w =
            key[round].w
            ^ Te0[(ciphertext.w >> 24) & 0xFF]
            ^ Te1[(ciphertext.x >> 16) & 0xFF]
            ^ Te2[(ciphertext.y >>  8) & 0xFF]
            ^ Te3[(ciphertext.z >>  0) & 0xFF];

        ciphertext = temp;
    }