In wireless mesh networks, during handoff process, the mobile client needs to authenticate with other nodes. It is necessary to ensure secure communication between the mobile client and mesh nodes. However, using the conventional public key infrastructure requires a large overhead of storage requirement, since it has to deal with the management of the public key certifications. In the present paper, an ID-based signcryption authentication algorithm for intra- and inter-domain handoff has been proposed. In this solution, a proxy-based hierarchical network has been considered. To reduce the handoff latency, a caching-list-based pre-fetching technique has been applied. During inter-domain handoff, authentication messages are encrypted using ID signcryption and signed by the mesh clients. Thus, the proposed algorithm ensures high security along with fast handoff. It has been observed from simulation results that the proposed algorithm reduces the percentage of compromised nodes, authentication delay, and communication cost with increased packet delivery ratio.