DES algorithm decryption process is the same, the only difference is that the first iteration used Subkey K15, K14 ,......, second last with K0, the algorithm itself without any change.

DES算法解密过程是，区别仅仅在于第次迭代时用子密钥K15，第二次K14、......，最后次用K0，算法本并没有任何变。