public static void verifyPassword()
    {
        #region readUserInput
        string userInput = "";
        Console.Write("Enter Password:");

        SecureString pwd = new SecureString();
        while (true)
        {
            ConsoleKeyInfo i = Console.ReadKey(true);
            if (i.Key == ConsoleKey.Enter)
            {
                break;
            }
            else if (i.Key == ConsoleKey.Backspace)
            {
                if (pwd.Length > 0)
                {
                    pwd.RemoveAt(pwd.Length - 1);
                    Console.Write("b b");
                }
            }
            else
            {
                pwd.AppendChar(i.KeyChar);
                Console.Write("*");
            }
        }
        IntPtr bstr = Marshal.SecureStringToBSTR(pwd);
        try
        {
            //Console.WriteLine(Marshal.PtrToStringBSTR(bstr));
            userInput = Marshal.PtrToStringBSTR(bstr);
        }
        finally
        {
            Marshal.FreeBSTR(bstr);
        }
        #endregion

        #region theRealPass
        string password = "123456";
        string pass = "";
        SecureString thePass = new SecureString();
        Array.ForEach(password.ToArray(), thePass.AppendChar);
        thePass.MakeReadOnly();
        password = "";
        IntPtr bstr2 = Marshal.SecureStringToBSTR(thePass);
        //pass = Marshal.PtrToStringBSTR(bstr);
        try
        {
            //Console.WriteLine(Marshal.PtrToStringBSTR(bstr));
            pass = Marshal.PtrToStringBSTR(bstr2);
        }
        finally
        {
            Marshal.FreeBSTR(bstr2);
        }
        #endregion
        bool a = true;
        a = (userInput == pass);

        if (a)
        {
            userInput = "";
            pass = "";
            Console.WriteLine("good");
        }
        else
        {
           Console.WriteLine("nWrong Password,please try again");
            wrongPassword();
        }

    }
    public static void wrongPassword()
    {
        int numbers = 5;
        for (int i = 0; i < numbers; i++)
        {
            verifyPassword();
        }


    }