sha-256

凯撒密码作为一种最为古老的对称加密体制，在古罗马的时候都已经很流行，他的基本思想是：通过把字母移动一定的位数来实现加密和解密。例如，如果密匙是把明文字母的位数向后移动三位，那么明文字母B就变成了密文的E，依次类推，X将变成A，Y变成B，Z变成C，由此可见，位数就是凯撒密码加密和解密的密钥。个人原创。(Caesar password as one of the most ancient symmetric encryption system in ancient Rome have been very popular, his basic idea is: by the letters move a certain number of bits to achieve encryption and decryption. For example, if the key is the number of bits of plaintext letters backward move three, the plaintext letter B into a ciphertext E, and so on, X will become Y-become a B,, and Z becomes C Thus, the median is the Caesar cipher encryption and decryption keys. Personal originality.)

3Des encryption of text from a file, 3DES-EDC-CBC , using 3 keys

利用C语言实现的cmac算法，该cmac基于AES。程序清晰有注释便于查看(The use of C language cmac algorithm, the cmac based AES. There are clear and easy to view program notes)

基本的DES加密算法，可以实现一些基本的功能，但是大型计算不适合(The basic DES encryption algorithm)

md5及sha-1算法及验证文件，vc6.0调试无误(md5 and sha-1 algorithm and verification documents, vc6.0 debug and correct)

自己写的一份RSA算法。可正常执行。控制台程序。(Write your own copy of the RSA algorithm. Can be performed normally. Console program.)

VB6.0调用Windows系统的API计算MD5码。这个代码跟网上流行的代码相比，具有代码简洁，维护方便，运行效率高等优点。运行速度比用纯VB6实现的快得多。(VB6.0- Call Windows system API calculate MD5 code. This code is compared with the popular online code, with code simple, easy maintenance, high efficiency. Runs faster than pure VB6 realize faster.)

这是一个小程序,凯撒解密,自己写的,以后还会扩展的(This is a simple program for a example of ceasar cipher. It is produced by myself and I want to extend it to a substitution cipher program in some days.)

检测CRC编码 看CRC编码在传输后是否有错误 有变动 (Detection CRC codes to see whether the CRC coding errors in the transmission there is a change)

DES加密算法，初始置换、密钥置换、密钥循环、密钥压缩置换、数据扩展置换、、S盒替换、P盒置换、末置换 (DES encryption algorithm, the initial replacement, key replacement, key loops, key compression replacement, data expansion permutation,, S cartridge replacement, P cartridge replacement, replacement end)