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；-C# encryption and decryption procedures and source code, encryption key two steps, first select the file, step right into a randomly generated encryption key Key, and IV, using the sender' s private key signing random key, use the recipient public key encryption secret keys and signatures, using random key encrypted data packet using the DES algorithm, MD5 summary is generated- " with the sender' s private key signature