Certificateless Hybrid Signcryption Scheme with Known Session-Specific Temporary Information Security

The hybrid signcryption scheme based on certificateless public key cryptography avoids the complexity of certificate management existing in the traditional public key cryptography and the inherent key escrow problem existing in identity-based public key cryptography. The certificateless hybrid signcryption scheme combined with certificateless signcryption key encapsulation mechanism and data encapsulation mechanism can dispose the messages with arbitrary length while conventional certificateless signcryption schemes cannot. Meanwhile, almost all the proposed certificateless hybrid signcryption schemes cannot survive against the known session-specific temporary information security (KSSTIS) attack. In this paper we propose an efficient certificateless hybrid signcryption scheme, and formally prove its security in random oracle model under the assumption of Diffie-Hellman mathematical hard problems. Compared with the previous schemes, our scheme has the advantage of lower computational cost by reducing the amount of bilinear pairing computation. Moreover, our scheme achieves KSSTIS attribute.