An Identity-Based Ring Signcryption Scheme in Ideal Lattice

The existing signcryption schemes based on bi-linear pairings were proved to be insecure in quantum computing environment. Lattice is simple in operation, and the difficult problems based on lattice are hard to solve. In order to resist the quantum attack, we presented an identity-based ring signcryption scheme that is provably secure under the standard model by using the Ducas’ ideal lattice technology, which is based on the assumption of the hardness of lattice problem small integer solutions (SIS). This scheme mainly includes four algorithms: Keygen(), Extract(), Signcrypt(), Unsigncrypt(). To some extent, the scheme in this paper that has a high practical value in electronic cash payment system, security certification lightweight authentication and other fields shortens the bytes of private key, public key and the signcryption, improves the operation efficiency. The security of scheme also indirectly ensure the security in electronic cash payment system, security certification and so on.