Pseudorandomness of Optimal MISTY-Type Structure
优化MISTY型结构的伪随机性

The four round MISTY-type and the three round dual MISTY-type transformation are optimized by replacing the first round pseudorandom permutation with XOR-universal permutation and employing identical pseudorandom permutation in the second and the third round. Thus the running time is shortened and the number of keys are saved by reducing the number of pseudorandom permutation. Hence the running cost is debased greatly. At the same time, the security remains.