Binary Information Press
Recently, the researcher proposed a certificateless signature scheme which is provably secure in the standard model. In 2008, the researcher pointed out that Liu et al.'s scheme is insecure against a malicious-but passive KGC attack and then proposed an improvement to withstand such an attack. In this paper, the authors will show that this improvement is unfortunately still vulnerable to malicious-but-passive KGC attack, which is contrary to their claims. Moreover, it is vulnerable to key replacement attack. They further propose a novel certificateless signature scheme which can be proven secure against the attacks mentioned above in the standard model.