Аннотация:In the grid security infrastructure (GSI), cross-domain authentication is based on traditional PKI cross certificate, which brings about problems of certificates management. Encouragingly, identity-based cryptography (IBC) can overcome these problems for its certificate-free feature. Therefore, an identity-based signcryption scheme is proposed in order to meet the requirement of cross-domain authentication. Based on this scheme, identity-based authentication model for multi-domain and mutual entity authentication protocol are presented. Compared with certificate-based PKI authentication framework in terms of communication and computation cost, this model is more efficient and lightweight.