As said in the doc: https://github.com/ZF-Commons/zfc-rbac/blob/master/config/zfc_rbac.global.php.dist#L28
The service name for the identity_provider
option must return an instance that implements ZfcRbac\Identity\IdentityProviderInterface. We provide a built-in one that uses AuthenticationService: https://github.com/ZF-Commons/zfc-rbac/blob/master/config/zfc_rbac.global.php.dist#L31
I recommend you staying with the default. To construct ZfcRbac\Identity\AuthenticationIdentityProvider
, ZfcRbac fetches Zend\Authentication\AuthenticationService
from its factory. So what you need actually is replacing AuthService in your config by 'Zend\Authentication\AuthenticationService'.