C#加密解密程序及源代码，加密主要分两步进行，第一步选择文件，第二步随机产生对成加密钥匙Key和IV、使用发送者私钥签名随机密钥，使用接收者公钥加密密钥和签名、利用随机密钥使用DES算法分组加密数据、MD5摘要生成-->用发送者私钥签名；-Encryption and decryption procedures and source code in C#, encryption, mainly in two steps, the first step to select the file, the second step randomly generated as the encryption key Key and IV using the sender' s private key signature random key using the recipient public key encryption key key and signature, using the random key packet to encrypt data using the DES algorithm, the MD5 digest generation->　sender' s private key signature