C#

public static void Decrypt(byte[] toEncryptArray, bool useHashing)
        {
            System.Configuration.AppSettingsReader settingsReader = new AppSettingsReader();
            //Get your key from config file to open the lock!
            string key = (string)settingsReader.GetValue("SecurityKey", typeof(String));

            if (useHashing)
            {
                MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
                D_keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
                hashmd5.Clear();
            }
            else
                D_keyArray = UTF8Encoding.UTF8.GetBytes(key);

            TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
            tdes.Key = D_keyArray;
            tdes.Mode = CipherMode.ECB;
            tdes.Padding = PaddingMode.PKCS7;

            ICryptoTransform cTransform = tdes.CreateDecryptor();
            byte[] D_resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
           
             //  the D_resultArray always get a null value
            tdes.Clear();
       }