Encryption-and-decryption

RSA公钥加密程序，可实现密钥对生成，加解密任意字符串功能。MFC界面。(RSA public key encryption program, enabling the key pair generation, encryption and decryption functions of arbitrary strings. MFC interface.)

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)

VC编写的简单DES加密程序，密钥由用户手动输入，可加密字符串(VC prepared by the simple DES encryption program, the key to manually input by the user)

我自己编写的rsa算法，实现了加密和解密功能

21加密算法,用vB语言编写实现,可了解各种加密算法的结构(21, encryption algorithm, and realize vB languages, can understand the structure of a variety of encryption algorithms)

RSA加密算法，实现对文字的加密，将文字转化成数字后用RSA原理进行加密(This is RSA encryption algorithm)

说明：  编制程序，将输入的一行字符以加密的形式输出，然后将其解密，解密的字符串序列与输入的正文相比较，吻合时输出解密的正文，否则解密失败。 加密时，将每个字符的ascii码依次反复加上“4962873”中的数字，并在32（‘’）~122（‘z’）之间作模运算。解密与加密的顺序相反。例如输入正文“the result of 3 and 2 is not 8” 结果为： (Programming, the input line character output in an encrypted form, and then decrypted, the decrypted text sequence of characters compared with the input, output to decrypt the body of the agreement, otherwise the decryption failed. Encryption, ascii code of each character in turn repeatedly with &quot 4962873&quot in the figures, and 32 (' ' )~ 122 (' z' ) as a model between the operations. Decryption and encryption in reverse order. For example, enter the text &quot the result of 3 and 2 is not 8&quot results:)

说明：  六种加密算法源码，包括CRC32校验，DES加密，MD5，rsa数字签名，RSA演示，简单加密(Six encryption algorithm source code, including the CRC32 checksum, DES encryption, MD5, rsa digital signature, RSA presentation, simple encryption)

sm4国密对称算法源码和使用sample，请参考。。(sm4 source code sample)

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.)