addRoundKey(0);
            for (int i = 1; i < rounds; i ++) {
                    subBytes();
                    shiftRows();
                    mixColumns();
                    addRoundKey(i);
            }
            subBytes();
            shiftRows();
            addRoundKey(rounds);

addRoundKey(rounds);
            for (i = 1; i < rounds; i ++) {
                    invShiftRows();
                    invSubBytes();
                    addRoundKey(rounds - i);
                    invMixColumns();
            }
            invShiftRows();
            invSubBytes();
            addRoundKey(0);

addRoundKey(rounds);
            for (i = 1; i < rounds; i ++) {
                    invShiftRows();
                    invSubBytes();
                    invMixColumns();
                    addRoundKeyAlreadyInvMixed(rounds - i);
            }
            invShiftRows();
            invSubBytes();
            addRoundKey(0);