常用的加密解密方法

using System;
using System.Security.Cryptography;
using System.Text;

namespace AttendService
{
    public static class DESEncrypt
    {
        #region ========加密========

        private static string txtKey = "PatrickpanP=";
        private static string txtIV = "LiuJineagel=";

         /// <summary>
        /// 加密資料
        /// </summary>
        /// <param name="Text"></param>
        /// <param name="sKey"></param>
        /// <returns></returns>
        public static string Encrypt(string Text)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray;
            inputByteArray = Encoding.Default.GetBytes(Text);
           
//des.Key =
ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey,
"md5").Substring(0, 8));
            //des.IV =
ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey,
"md5").Substring(0, 8));
            des.Key = Convert.FromBase64String(txtKey);
            des.IV = Convert.FromBase64String(txtIV);
            System.IO.MemoryStream ms = new System.IO.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);
            }
            return ret.ToString();
        }

        #endregion

        #region ========解密========

        /// <summary>
        /// 解密資料
        /// </summary>
        /// <param name="Text"></param>
        /// <param name="sKey"></param>
        /// <returns></returns>
        public static string Decrypt(string Text)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            int len;
            len = Text.Length / 2;
            byte[] inputByteArray = new byte[len];
            int x, i;
            for (x = 0; x < len; x++)
            {
                i = Convert.ToInt32(Text.Substring(x * 2, 2), 16);
                inputByteArray[x] = (byte)i;
            }
           
//des.Key =
ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey,
"md5").Substring(0, 8));
            //des.IV =
ASCIIEncoding.ASCII.GetBytes(System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(sKey,
"md5").Substring(0, 8));
            des.Key = Convert.FromBase64String(txtKey);
            des.IV = Convert.FromBase64String(txtIV);
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
            cs.Write(inputByteArray, 0, inputByteArray.Length);
            cs.FlushFinalBlock();
            return Encoding.Default.GetString(ms.ToArray());
        }

        #endregion
    }
}