指定键的大小对于此算法无效。
 CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(FKEY, FIV), CryptoStreamMode.Write);整个代码如下
using System;
using System.Collections.Generic;
using System.Text;
using System.Security.Cryptography;
using System.IO; 
namespace CDES
{
    public class CDES
    {
        static byte[] FIV;
        static byte[] FKEY;
        public CDES()
        {
            //   TODO:   在此处添加构造函数逻辑   
            this.DefaultInit();
        }        ///   <summary>   
        ///   默认键值和初始向量   
        ///   </summary>   
        private void DefaultInit()
        {
            byte[] IV =   { 155, 103, 246, 8, 36, 99, 234, 36 };
            byte[] key ={ 142, 16, 93, 156, 78, 4, 218, 132 };
             FIV = IV;
             FKEY = key;        }        ///   <summary>   
        ///   采用标准   64位   DES   算法加密   
        ///   </summary>   
        ///   <param   name="strText">要加密的字符串</param>   
        ///   <returns>返回加密后的字符串</returns>   
        public static string Encrypt(string strText)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            MemoryStream ms = new MemoryStream();
            CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(FKEY, FIV), CryptoStreamMode.Write);
            StreamWriter sw = new StreamWriter(cs);
            sw.Write(strText);
            sw.Flush();
            cs.FlushFinalBlock();
            ms.Flush();
            return Convert.ToBase64String(ms.GetBuffer(), 0, Convert.ToInt32(ms.Length));
        }
        ///   <summary>   
        ///   标准64位DES解密   
        ///   </summary>   
        ///   <param   name="strText">要解密的字符串</param>   
        ///   <returns>返回解密后的字符串</returns>   
        public static string Decrypt(string strText)
        {
            DESCryptoServiceProvider des = new DESCryptoServiceProvider();
            byte[] inputByteArray = Convert.FromBase64String(strText);
            MemoryStream ms = new MemoryStream(inputByteArray);
            CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(FKEY, FIV), CryptoStreamMode.Read);
            StreamReader sr = new StreamReader(cs);
            return sr.ReadToEnd();
        }    }   }
在新建的网页页面中调用
protected void Page_Load(object sender, EventArgs e)
    {
string password="Data Source=192.168.1.15;Initial Catalog=AYLData;User ID=sa;Password=water345  ";
Response.Write(CDES.CDES.Encrypt(password));
    }