Abstract:

Heterogeneous signcryption can be used to guarantee the confidentiality and the unforgeability in the different cryptographies. By analyzing some existing heterogeneous signcryption schemes, it is found that those schemes are slow in operation and more suitable for encrypting short messages. Hybrid signcryption can efficiently encapsulate symmetric keys and securely transmit data. This paper proposes a heterogeneous hybrid signcryption scheme for the traditional public key cryptosystem (TPKC)-certificate public key cryptosystem (CLPKC) under 5G network.The scheme can not only ensure the confidentiality and the unforgeability from TPKC to CLPKC, but also fastly handle the arbitrary length messages. Based on the bilinear Diffie-Hellman difficulty hypothesis, the Diffie-Hellman difficulty hypothesis and the discrete logarithm difficulty problem, it is proved that the scheme satisfies the unforgeability under the adaptive ciphertext attack and the unforgeability under the adaptive selection message.Based on the bilinear of Diffie-Hellman difficulty hypothesis, computational Diffie-Hellman and Discrete logarithm, under the random oracle model.The scheme posseses indistinguishability against adaptive chosen ciphertext attack and existential unforgeability against adaptive chosen messages attack.

Key words: heterogeneous signcryption, hybrid signcryption, bilinear Diffie-Hellman problem, Diffie-Hellman problem, discrete logarithm problem