DES加密

 public static class DesHelper
 {
        private const string key = "weihuajt";

        private const string iv = "hijklmno";

        /// <summary>
        /// DES加密
        /// </summary>
        /// <param name="data">加密数据</param>
        /// <param name="key">8位字符的密钥字符串</param>
        /// <param name="iv">8位字符的初始化向量字符串</param>
        /// <returns></returns>
        public static string DESEncrypt(string data, string key = key, string iv = iv)
        {
            byte[] byKey = Encoding.ASCII.GetBytes(key);
            byte[] byIV = Encoding.ASCII.GetBytes(iv);

            using (DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider())
            {
                using (MemoryStream ms = new MemoryStream())
                {
                    using (CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateEncryptor(byKey, byIV), CryptoStreamMode.Write))
                    {
                        using (StreamWriter sw = new StreamWriter(cst))
                        {
                            sw.Write(data);
                            sw.Flush();
                            cst.FlushFinalBlock();
                            sw.Flush();
                            return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);
                        }
                    }
                }

            }
        }

        /// <summary>
        /// DES解密
        /// </summary>
        /// <param name="data">解密数据</param>
        /// <param name="key">8位字符的密钥字符串(需要和加密时相同)</param>
        /// <param name="iv">8位字符的初始化向量字符串(需要和加密时相同)</param>
        /// <returns></returns>
        public static string DESDecrypt(string data, string key = key, string iv = iv)
        {
            byte[] byKey = Encoding.ASCII.GetBytes(key);
            byte[] byIV = Encoding.ASCII.GetBytes(iv);

            byte[] byEnc;
            try
            {
                byEnc = Convert.FromBase64String(data);
            }
            catch
            {
                return null;
            }

            using (DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider())
            {
                using (MemoryStream ms = new MemoryStream(byEnc))
                {
                    using (CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateDecryptor(byKey, byIV), CryptoStreamMode.Read))
                    {
                        using (StreamReader sr = new StreamReader(cst))
                        {
                            return sr.ReadToEnd();
                        }
                    }
                }

            }
        }
    }