Cakephp 1.3, router and authentication problem

Trying to implements simple privileges for admin user. Don't need huge acl rules and groups system. There are admin users, overs - just registered users. They can't access actions with admin prefix. So It was implemented in cakephp1.2 version with following code in app_controller:

function isAuthorized() {
    if (isset($this->params[Configure::read('Routing.admin')])) {
    if ($this->Auth->user('admin') != 1) {
        return false;
    return true;

But in 1.3 Routing.admin had been deprecated. How to rewrite it for use with 1.3 framework? Need some help.