.net URL加密和解密

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Security.Cryptography;
using System.IO;
using System.Text;

/// <summary>
/// Class1 的摘要说明
/// </summary>
public class Security
{
    #region 加密Key
    string _QueryStringKey = "12345678"; //URL传输参数加密Key这个key可以自己设置支持8位这个东西很重要的
    #endregion

    #region 加密算法
    /// <summary>
    /// 加密算法
    /// </summary>
    /// <param name="QueryString"></param>
    /// <returns></returns>
    public string EncryptQueryString(string QueryString)
    {
        return Encrypt(QueryString, _QueryStringKey);
    }
    #endregion

    #region 解密算法
    /// <summary>
    /// 解密算法
    /// </summary>
    /// <param name="QueryString"></param>
    /// <returns></returns>
    public string DecryptQueryString(string QueryString)
    {
        return Decrypt(QueryString, _QueryStringKey);
    }
    #endregion

    public string Encrypt(string pToEncrypt, string sKey)
    {
        DESCryptoServiceProvider des = new DESCryptoServiceProvider(); //把字符串放到byte数组中

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

      
        des.Key = ASCIIEncoding.ASCII.GetBytes(sKey); //建立加密对象的密钥和偏移量
        des.IV = ASCIIEncoding.ASCII.GetBytes(sKey); //原文使用ASCIIEncoding.ASCII方法的GetBytes方法
        MemoryStream ms = new MemoryStream(); //使得输入密码必须输入英文文本
        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();
    }

    public string Decrypt(string pToDecrypt, string sKey)
    {
        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 = ASCIIEncoding.ASCII.GetBytes(sKey); //建立加密对象的密钥和偏移量，此值重要，不能修改
        des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
        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(); //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

        return System.Text.Encoding.Default.GetString(ms.ToArray());
    }

    public bool ValidateString(string EnString, string FoString, int Mode)
    {
        switch (Mode)
        {
            default:
            case 1:
                if (Decrypt(EnString, _QueryStringKey) == FoString.ToString())
                {
                    return true;
                }
                else
                {
                    return false;
                }

        }
    }

}