支持中文的DES加密

        //加密方法,支持中文
        public static string Encrypt(string pToEncrypt, string key, string iv)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            //把字符串放到byte数组中
            byte[] inputByteArray = Encoding.UTF8.GetBytes(pToEncrypt);
            //建立加密对象的密钥和偏移量
            //原文使用ASCIIEncoding.ASCII方法的GetBytes方法
            //使得输入密码必须输入英文文本
            des.Key = ASCIIEncoding.ASCII.GetBytes(key);
            des.IV = ASCIIEncoding.ASCII.GetBytes(iv);

            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);

            //Write the byte array into the crypto stream
            //(It will end up in the memory stream)
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();

            //Get the data back from the memory stream, and into a string
            StringBuilder ret = new StringBuilder();
            foreach (byte b in ms.ToArray())
            {
                //Format as hex
                ret.AppendFormat("{0:X2}", b);
            }
            ret.ToString();
            return ret.ToString();
        }

        //解密方法,支持中文
        public static string Decrypt(string pToDecrypt, string key, string iv)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            //Put the input string into the byte array
            byte[] inputByteArray = new byte[pToDecrypt.Length / 2];
            for (int x = 0; x < pToDecrypt.Length / 2; x++)
            {
                int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));
                inputByteArray[x] = (byte)i;
            }
            //建立加密对象的密钥和偏移量，此值重要，不能修改 
            des.Key = ASCIIEncoding.ASCII.GetBytes(key);
            des.IV = ASCIIEncoding.ASCII.GetBytes(iv);

            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);

            //Flush the data through the crypto stream into the memory stream
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();

            //Get the decrypted data back from the memory stream
            //建立StringBuild对象，CreateDecrypt使用的是流对象，必须把解密后的文本变成流对象   

            StringBuilder ret = new StringBuilder();
            return System.Text.Encoding.UTF8.GetString(ms.ToArray());
        }