.NET c#加密解密方法

		#region 加密
        /// <summary>  
        /// 加密  
        /// </summary>  
        /// <param name="strSource">需要加密的字符串</param>  
        /// <returns>加密後的字符串</returns>  
        [OperationContract]
        public string Md5Encrypt(string strSource)
        {
            //把字符串放到byte數組中  
            byte[] bytIn = System.Text.Encoding.Default.GetBytes(strSource);
            //建立加密對象的密鑰和偏移量          
            byte[] iv = { 102, 16, 93, 156, 78, 4, 218, 32 };//定義偏移量  
            byte[] key = { 55, 103, 246, 79, 36, 99, 167, 3 };//定義密鑰  
            //實例DES加密類  
            DESCryptoServiceProvider mobjCryptoService = new DESCryptoServiceProvider();
            mobjCryptoService.Key = iv;
            mobjCryptoService.IV = key;
            ICryptoTransform encrypto = mobjCryptoService.CreateEncryptor();
            //實例MemoryStream流加密密文件  
            System.IO.MemoryStream ms = new System.IO.MemoryStream();
            CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Write);
            cs.Write(bytIn, 0, bytIn.Length);
            cs.FlushFinalBlock();
 
            string strOut = System.Convert.ToBase64String(ms.ToArray());
            return strOut;
        }
        #endregion
 
        #region 解密
        /// <summary>  
        /// 解密  
        /// </summary>  
        /// <param name="Source">需要解密的字符串</param>  
        /// <returns>解密後的字符串</returns>  
        [OperationContract]
        public string Md5Decrypt(string Source)
        {
            //將解密字符串轉換成字節數組  
            byte[] bytIn = System.Convert.FromBase64String(Source);
            //給出解密的密鑰和偏移量，密鑰和偏移量必須與加密時的密鑰和偏移量相同  
            byte[] iv = { 102, 16, 93, 156, 78, 4, 218, 32 };//定義偏移量  
            byte[] key = { 55, 103, 246, 79, 36, 99, 167, 3 };//定義密鑰  
            DESCryptoServiceProvider mobjCryptoService = new DESCryptoServiceProvider();
            mobjCryptoService.Key = iv;
            mobjCryptoService.IV = key;
            //實例流進行解密  
            System.IO.MemoryStream ms = new System.IO.MemoryStream(bytIn, 0, bytIn.Length);
            ICryptoTransform encrypto = mobjCryptoService.CreateDecryptor();
            CryptoStream cs = new CryptoStream(ms, encrypto, CryptoStreamMode.Read);
            StreamReader strd = new StreamReader(cs, Encoding.Default);
            return strd.ReadToEnd();
        }
        #endregion