Dynamic asymmetric group key agreement for ad hoc networks

A group key agreement protocol allows a set of users to establish a common symmetric key via open networks. Dynamic asymmetric group key agreement means that a dynamic set of users form a temporary group and negotiate to share a public encryption key, so that anyone can send message securely and efficiently to the temporary group. Users can join or leave the group efficiently without triggering a completely new key agreement protocol, which will greatly benefit the users in ad hoc networks. We describe a generic construction of dynamic asymmetric group key agreement by combining a conventional authenticated group key agreement, a public key encryption and a multi-signature. Then we give out an instance with constant rounds of interactions and constant transmission cost for each participant.