算法流程

1.将要处理的二进制串进行IP置换



2.将密钥进行PC1置换(64位转为56位),



3.进行16轮操作,对于第i轮操作:



1)将上一次得到的PC1密钥(级除去第一次外,其他的都经过移位处理)的结果左右部分(各28位)分别循环左移1位或2位,然后将移位后的密钥进行PC2[i]置换.



2)将处理串均等分为左右两串Li,Ri(各32位),然后将右串Ri通过E盒拓展为新的右串R (48位),R 与上一步得到的PC2[i]子密钥进行异或操作,结果通过S盒输出(48为转为32位),然后通过P盒直接置换,再与Li异或.



3)将Ri赋给作出Li,R 赋值给Ri.



4)合并处理串StrText=Li+Ri.



4.将最新的处理串进行IP_1置换,置换结果即为所求的加密串或解密串



加密解密的区别



在每轮操作中,加密使用的PC2密钥顺序为0~15,解密使用的PC2密钥顺序为15~0.

更多0-The algorithm flow would have to deal with the binary string replacement IP key PC1 replacement (64 into 56), 3. Conducted 16 operations, for the i-th round operation: 1) the last PC1 key (removal of the first, the other after shift processing), about (28), respectively, rotate left one or two, then the shift key PC2 [i] replacement. 2) will handle the string equalization is divided into right and left bunches Li, Ri (32), and then the right string Ri develop new right string R ' (48-bit), R'　is obtained in the previous step through the E box PC2 [i] subkey XOR operation results through the S-box output (48 into 32), and then through the P box direct replacement, with Li the XOR. 3) Ri is assigned to make Li, R '　assignment to Ri. 4) the combined processing string StrText = Li+Ri, 4. latest processing string for IP_1 replacement, replacement result is encrypted string or ask the the decrypted string encryption and decryption difference in each round operation, encryption use