Provably Secure and Efficient Multi-receiver Identity-Based Generalized Signcryption Scheme

Generalized signcryption (GSC) can adaptively work as an encryption scheme, a signature scheme or a signcryption scheme with only one algorithm and one key pair, which is very suitable for storage-constrained environments, like the embedded systems, smart cards and wireless sensor networks. In this paper, a multi-receiver identity-based generalized signcryption scheme (MID-GSC) is proposed, the formal definition and security notions are defined, and the concrete scheme is proved to be confidential under the bilinear Diffie-Hellman assumption and existentially unforgeable under the computational Diffie-Hellman assumption in the random oracle model. By using the randomness reuse technique, the scheme only needs one pairing computation to generally sign crypt a single message for n receivers. Compared with the traditional approach, the new scheme is of high efficiency.