Identity-Based Authenticated Asymmetric Group Key Agreement

The asymmetric group key agreement (AGKA) protocol enables external users to securely send messages to group members. With the development of large-scale collaborative computing in distributed network, the members who participate in collaborative computing may come from different domains, different time zones and different cloud ends networks. Existing AGKA can not meet the security of information exchange among group members that come from cross-domain or heterogeneous network, and it is only secure against passive attacks which are too weak to capture the attacks in the real world. In this paper, we formalize an active security model for identity-based authentication asymmetric group key agreement (IB-AAGKA) protocol. Our protocol achieves an asymmetric group key agreement only one round, to resolve the problem that is hard to find a trusted party to serve as a dealer in a regular broadcast scheme, and is inconvenient to require all the parties in differences time zones to stay online concurrently to implement a (two-round or multi-round) regular GKA protocol. Our protocol can also achieve anonymous authentication. It supports the dynamic group key update of nodes for forward secrecy and backward secrecy of group key. Our protocol is proven secure under the decisional bilinear Diffie-Hellman (DBDH) problem assumption, and the performance analysis show that the proposed scheme is highly efficient.