Cryptanalysis and improvement on a certificateless encryption scheme in the standard model
Limin Shen, Futai Zhang, Yinxia Sun, Sujuan Li · International Journal of Information and Computer Security · 2014
Certificateless public key cryptography (CL-PKC) is an important type of public key cryptography, which effectively solves the inherent key escrow problem in identity-based public key cryptography. As the adversarial models in CL-PKC are relatively complex, designing efficient and secure certificateless encryption schemes in the standard model has been an interesting and challenging research topic. In this paper, we give cryptanalysis to an existing certificateless encryption scheme in the standard model. We show its insecurity by demonstrating two kinds of attacks. Then, we modify the original scheme to obtain a secure one. A rigorous security proof of the modified scheme is presented in the standard model based on the decisional bilinear Diffie-Hellman (DBDH) assumption and decisional truncated q -ABDHE assumption.