asp.net MD5数据加密和解密

#region ========加密======== 
/// <summary>
/// 加密
/// </summary>
/// <param name="Text"></param>
/// <returns></returns>
 public static string Encrypt(string Text) 
        {
return Encrypt(Text, "Tony"); 
        }
/// <summary> 
/// 加密数据 
/// </summary> 
/// <param name="Text"></param> 
/// <param name="sKey"></param> 
/// <returns></returns> 
 public static string Encrypt(string Text, string sKey) 
        {
            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)); 
            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

--------------------------------------我是华丽的分割线---------------------------

#region ========解密======== 
/// <summary>
/// 解密
/// </summary>
/// <param name="Text"></param>
/// <returns></returns>
 public static string Decrypt(string Text) 
        {
return Decrypt(Text, "Tony"); 
        }
/// <summary> 
/// 解密数据 
/// </summary> 
/// <param name="Text"></param> 
/// <param name="sKey"></param> 
/// <returns></returns> 
 public static string Decrypt(string Text, string sKey) 
        {
            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)); 
            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