An Efficient Online/Offline Heterogeneous Signcryption Scheme With Equality Test for IoVs

The privacy and authenticity of propagated messages are two important goals in Internet of Vehicles (IoVs). Most of existing signcryption schemes can satisfy above requirements, but they are rigidly compatible for a single cryptosystem rather than a heterogeneous system consisting of different cryptographic mechanisms. In this paper, we construct an efficient online/offline heterogeneous signcryption scheme with equality test (OOHSC-ET), in which the signcrypted message is delivered from certificateless cryptosystem (CLC) to public key infrastructure (PKI) system for information compatibility. Besides, this construction allows the cloud server to perform the equality test, to determine whether the different ciphertexts contain the same plaintext without unsigncryption, as a feasible solution for searching ciphertext in heterogeneous environment. In addition, the signcryption phase can be separated into online and offline manners, the former conducts the lightweight operation, while the latter initializes the heavy and preparative operation. In this way, the security and efficiency are both preserved. Finally, the security proof and performance analysis demonstrate that the OOHSC-ET scheme is more suitable for the payment operation in terms of IoVs.