International Association
for Cryptologic Research

Signcryption is a relatively new cryptographic technique that is supposed to fulfill the functionalities of digital signature and encryption in a single logical step and can effectively decrease the computational costs and communication overheads in comparison with the traditional signature-then-encryption schemes, and aggregate signcryption scheme allows individual signcryption ciphertexts intended for the same recipient to be aggregated into a single (shorter) combined ciphertext without losing any of the security guarantees. In this paper, we present a new identity-based aggregate signcryption scheme using multilinear maps. To the best of my knowledge, our new scheme is the first identity-based aggregate signcryption scheme that admits unrestricted aggregation.