Many previous broadcast encryption schemes can only guarantee confidentiality but cannot verify integrity and authenticity for broadcast messages. In this paper, a broadcast signcryption protocol for ad hoc networks is proposed based on cluster-based structure. The proposed protocol not only guarantees confidentiality but also verifies integrity and authenticity for broadcast messages. More importantly, the proposed scheme enables the cluster head to robustly add or remove any cluster member without changing secret key of other cluster members. Moreover, the proposed protocol avoids massive message exchange for key setup among cluster members. The analysis of security and performance shows that the proposed protocol is secure, efficient, and more practical protocol for ad hoc networks.
