Add auth to some methods of API resource routes

I need to restrict access to the index resource so that people cant view all the submissions from a contact form.. is this possible to do via a route or what are people doing ?

Im using Laravel 5.2

Route::group(['prefix' => 'v1/api', 'middleware' => ['cors']], function(){

    Route::resource('contact', 'ContactFormController', ['except' => [
        'create', 'edit'
    ]]);  

});

via Chebli Mohamed