Efficient and secure certificateless signature scheme in the standard model

Summary Certificateless cryptography not only enjoys many advantages of identity‐based cryptography (IBC) but also eliminates the fatal drawback, which is called the key escrow in IBC. Most of the early certificateless signature schemes are secure based on the random oracle model, and nowadays, more and more researchers put emphasis on the scheme based on the standard model. In 2010, Xia et al. demonstrated that the previous schemes in the standard model cannot resist the public‐key‐replace attack. In 2012, for the purpose of overcoming the common drawback, Yu et al. presented a new certificateless signature scheme. However, under the public‐key‐replace attack and malicious‐but‐passive key generation center attack, this scheme is proven to be vulnerable. Moreover, there are too many bilinear pairings used in this scheme, which lead to its low computation efficiency. Aiming at the weakness of the scheme byYu et al., we propose a new certificateless signature scheme, which provides stronger security and higher computational efficiency than the existing schemes. In addition, according to the concept of Girault's trust level, the new scheme can reach trust level 3. Copyright © 2015 John Wiley & Sons, Ltd. To overcome the public‐key‐replace attack and malicious‐but‐passive KGC attack, which Yu et al.'s scheme suffers from, we propose a new certificateless signature scheme that provides stronger security. Because of reducing the bilinear pairing computations, we improve the computational efficiency. In addition, the new scheme can reach trust level 3, according to the concept of M. Girault's trust level.