A delegation request is submitted to a session-based authentication service, fulfillment of which involves granting an entity an access privilege to a computing resource. A session key is received from the session-based authentication service. The session key having been generated based at least in part on a restriction and a secret credential shared with the session-based authentication service and usable at least in part to prove possession of the access privilege to the computing resource. The session key is provided to the entity without providing the shared secret credential.