How can i decode hash value in laravel 5?

I have to convert my hash password into string.

here is my code.

<?php namespace App\Http\Controllers;
     use DB;
     use Auth;
     use Input;
     use Session;
     use Route;
     use Crypt;
     use Redirect;
     use Illuminate\Http\Request;
     use Illuminate\Http\Dispatcher; 

      $userdata = array(
                'email'     => $email,
                'password'  =>  Crypt::decrypt($password)
            );

when i use Crypt::decrypt i get error . error-

DecryptException in BaseEncrypter.php line 45:
The payload is invalid.

Can any one suggest me how can i do that?

Thanks.

via Chebli Mohamed