New Certificateless Generalized Signcryption Scheme for Internet of Things Environment

Certificateless generalized signcryption（CLGSC） scheme has been widely applied in resource-limited IoT environments for they could not only solve the problems of the certificate management and key escrow, but also serve as encryption, signature, or signcryption scheme according to the security requirements of the network.Firstly, concrete attacks are given to prove that Karati's scheme could not resist forgery attacks.This paper analyzes the essential reason why the adversaries can forge a valid signature or signcryption in CLGSC schemes.Then, an efficient certificateless generalized signcryption scheme without bilinear pairing is proposed.The proposed scheme is secure under the random oracle model based on the computational Diffie-Hellman problem and discrete logarithm problem.Finally, performance evaluation and comparison prove that the proposed scheme outperforms other CLGSC schemes in terms of computation cost, communication overhead and security functionalities.Therefore, the proposed scheme can provide