Provably Secure Identity-based Signature Scheme

With the continuous development of information society, information securityhas become more and more important. It is a striving goal for scholars to achieveInformation secure and reliable transmission in a less secure network environment.Along with the development of public-key cryptosystem, digital signature techno-logy has been also steadily forward.In the development process of digital signature technology, with differentapplications and requirements, there have been a variety of forms digitalsignatures, such as proxy signature, ring signature, threshold signature, identity-based signature and so on. No matter what kind of signature scheme, its safety andefficiency is one of the most concerned. In the random oracle model, which had beenconsidered secure signature scheme that is not safe. Therefore, our goal is to seek asecure and efficient digital signature scheme in the standard model.Nowadays，identity-based signature (IBS) has become a new research directionof public key encryption，and security is the most important factor for constructingan identity-based signature scheme. In recent years, to find an efficientidentity-based digital signature scheme in the standard model is a research focus inthe field of cryptography,and the security of the scheme is the most important factorfor a signature scheme. When designing an IBS scheme，security goals are usuallyconsidered by the standard of attack models．And using both security goal and attackmodels define the security．This paper analysis and research some identity-based signature scheme andsome identity-based proxy ring signature scheme on the basis of previous work,proposes a new provably secure identity-based signature scheme and a new provablysecure identity-based proxy ring signature scheme in the standard model.This paper proposes a new efficient and provably secure identity-basedsignature scheme．The scheme is existentially unforgeable against adaptive chosenmessage attack under the computational Diffie-Hellman assumption in the standardmodel.Compared with existing similar scheme,the scheme enjoys less publicparameters and higher efficiency．Using the method of waters for constructing private key, an efficient proxy ringsignature scheme based on identity and bilinear pairings is presented, and discussedthe scheme is satisfied to the safety requirements.It has no computational cost of bilinear pairings at signature generation and only need two pairings computation atsignature verification.Compared with the existing well-known signature schemes,this scheme has more efficiency.