An ad hoc network is a collection of wireless mobile hosts forming a temporary network without the aid of any established infrastructure or centralized administration. This exibility in space and time induces new challenges towards the security infrastructure needed to support secure unicast and multicast communications. Especially, traditional group key management architectures meant for wired networks are not appropriate in such environment due to high dynamics and mobility of nodes. In this paper, we propose an enhanced hybrid key management protocol for secure multicast dedicated to operate in ad hoc networks. Built on a protocol called BAAL dedicated to key distribution in wired networks, our approach integrates threshold cryptography and the services of the AKMP protocol to deliver fast, efficient and mobility aware key distribution in a multicast service.