页面传值的加密解密

<a href="../job/news.aspx?id=<%#DataBinder.Eval(Container.DataItem, "id")%>" target="_blank">
我想对id 进行ＭＤ５加密，到news．aspx页面解密，怎么做啊？各位帮帮忙啊！　 --------------------编程问答-------------------- 对字符串string1加密：
string str1=System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(string1,"SHA1")
或者System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(string,"md5")

到news．aspx页面解密，可以对string2再加密得到str2，然后比较str1==str2 --------------------编程问答-------------------- 如果想正向解密的话，使用des --------------------编程问答-------------------- 用这个吧
在引用using System.Security.Cryptography;

    const string KEY_64 = "VavicApp";//注意了，是8个字符，64位

    const string IV_64 = "VavicApp";
    public string Encode(string data)
    {
        byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
        byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

        DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
        int i = cryptoProvider.KeySize;
        MemoryStream ms = new MemoryStream();
        CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateEncryptor(byKey,byIV), CryptoStreamMode.Write);

        StreamWriter sw = new StreamWriter(cst);
        sw.Write(data);
        sw.Flush();
        cst.FlushFinalBlock();
        sw.Flush();
        return Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);

    }

    public string Decode(string data)//解密
    {
        byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(KEY_64);
        byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(IV_64);

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

        DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
        MemoryStream ms = new MemoryStream(byEnc);
        CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateDecryptor(byKey,byIV), CryptoStreamMode.Read);
        StreamReader sr = new StreamReader(cst);
        return sr.ReadToEnd();
    } --------------------编程问答-------------------- <a href="../job/news.aspx?id= <%#DataBinder.Eval(Container.DataItem, "id")%>" target="_blank">
id= <%#DataBinder.Eval(Container.DataItem, "id")%>
改为：DataBinder.Eval(Container.DataItem, "id")
id= <%# System.Web.Security.FormsAuthentication.HashPasswordForStoringInConfigFile(DataBinder.Eval(Container.DataItem, "id").ToString(),"md5") %>" --------------------编程问答-------------------- 不要考虑用MD5加密，MD5是不可逆的，也就是不能解密

用别的加密方法，比如DES
参考一下：
http://blog.csdn.net/jjhua/archive/2007/10/28/1850469.aspx --------------------编程问答-------------------- MD5不可逆

补充：.NET技术 ,  ASP.NET