Efficient Certificate-based Signature Scheme Research Articles

Efficient certificate-based signature scheme with strong designated verifier

Concerning the flaw that it needs a fully credible third party in ID-based strong designated verifier signature and the low efficiency of existing schemes,taking the advantage of Certificate Authority(CA)'s low trust level in certificate-based public key cryptography,a new strong designated verifier signature scheme was proposed in this paper.Furthermore,the formal security analysis under assumed Bilinear Diffie-Hellman(BDH) problem in the random oracle model was presented.Performance analysis shows the scheme meets all properties of strong designated verifier signature schemes and enjoys higher correspondence efficiency used in bandwidth limited environment since the signature length is just one of the group elements.

Provably secure certificate-based signature scheme without pairings

In order to simplify certificate management in traditional public key cryptography and solve the key escrow problem in identity-based cryptography, the notion of certificate-based cryptography was introduced. Recently, Ming and Wang proposed a certificate-based signature scheme without pairings. They claimed that the scheme was existentially unforgeable against adaptive chosen message and identity attacks in the random oracle. In this paper, we show that the scheme is insecure against a malicious certifier under existing security model. We also propose a new efficient certificate-based signature scheme without pairings, which is proven secure in the random oracle model. Compared with the existed certificate-based signature schemes without parings, our scheme enjoys shorter signature length and less operation cost.

Cryptanalysis of a Certificate-Based on Signature Scheme

Certificate-based cryptosystem combines the advantage of both traditional public key cryptosystem and identity based cryptosystem as it avoids the usage of certificates and resolves the key escrow problem. Recently, Liu et al. proposed a short and efficient certificate-based signature scheme and showed that the scheme was secure in the random oracles. In this paper, we show that Liu et al.’s certificate-based signature scheme is universally forgeable by a Type I adversary who models an uncertified entity and can replace the public keys of entities at will, but is not allowed to obtain the target user's certificate.