In one embodiment, an apparatus associated with securing a Resource Reservation Protocol (RSVP) with dynamic group keying is provided. The apparatus may include a group key logic that interacts with a dynamic group key management logic. The dynamic group key management logic provides a group key to members of a set of RSVP-capable devices. The apparatus also includes an RSVP authentication logic to determine whether a received RSVP message was provided by a member of the set of RSVP-capable devices. The determination is made using implicit authorization that depends on the group key and that does not depend on a challenge/response protocol. In one embodiment the apparatus is a router.