c# DES 加密解密方法

#region 密钥

        private static string key = "abcd1234";                                   //密钥(长度必须8位以上)   

        #endregion



        #region DES加密

        public static string EncryptString(string pToEncrypt)
        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();

            byte[] inputByteArray = Encoding.UTF8.GetBytes(pToEncrypt);





            des.Key = UTF8Encoding.UTF8.GetBytes(key);

            des.IV = UTF8Encoding.UTF8.GetBytes(key);

            MemoryStream ms = new MemoryStream();

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



            cs.Write(inputByteArray, 0, inputByteArray.Length);

            cs.FlushFinalBlock();



            StringBuilder ret = new StringBuilder();

            foreach (byte b in ms.ToArray())
            {

                ret.AppendFormat("{0:X2}", b);

            }

            ret.ToString();

            return ret.ToString();

        }

        #endregion



        #region DES解密

        public static string DecryptString(string pToDecrypt)
        {

            DESCryptoServiceProvider des = new DESCryptoServiceProvider();



            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;

            }



            des.Key = UTF8Encoding.UTF8.GetBytes(key);

            des.IV = UTF8Encoding.UTF8.GetBytes(key);

            MemoryStream ms = new MemoryStream();

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

            cs.Write(inputByteArray, 0, inputByteArray.Length);

            cs.FlushFinalBlock();



            StringBuilder ret = new StringBuilder();



            return Encoding.UTF8.GetString(ms.ToArray());

        }

        #endregion

需要引用的命名空间：
using System.IO;
using System.Text;
using System.Security.Cryptography;