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

#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