Strongly secure certificateless key-insulated signature secure in the standard model

To protect signing rights against the compromise of secret key, the key-insulated signature (KIS) has attracted a lot of attention from the industry and academia. It would be interesting to investigate the notion of KIS in the certificateless public key cryptography (CL-PKC) environment to solve the problem of certificate management and key escrow simultaneously. To capture the seeming neglected attack mounted by the malicious key generation center (KGC), a stronger security model for the CL-PKC should be considered. In this paper, we first show that the only known CL-KIS scheme is vulnerable against malicious KGC attack, and then propose the first CL-KIS scheme secure against malicious KGC attack, with security proof in the standard model.