Research On Provably Secure Certificateless Aggregate Signature Schemes

With the rapid development of the global computer network,a variety of online transactions is mushroomed,and thus more and more people began to pay attention to the issue of information security.Digital signature as one of the core technologies of information security,can provide authentication,integrity and non-repudiation for date transfer.Aggregate signature is a clever use of "compression" technology of digital signature,by aggregating n signatures for a signature,no longer need to verify each signature,so that the computation cost and communication cost has been greatly reduced,has a broad application prospect in resource constrained communication environment.Certificateless public key cryptosystem was proposed in 2003,not only to overcome the key escrow problem in public key cryptosystem in identity based,also successfully got rid of public key certificate management and storage in traditional public key cryptography.So,under the condition of the limited resources,certificateless aggregate signature scheme came into being.It not only combines their advantages,but also overcomes their shortcomings to a certain extent.Therefore,certificateless aggregate signature was preferred by more and more cryptography researchers.In this paper,through in-depth analysis of a series of certificateless aggregate signatures,two new schemes were designed.because they have certain advantages in efficiency,they have certain theoretical and practical value.The main results of this paper:1.The signature scheme based on k-CAA is deeply analyzed,and then a certificateless signature scheme with provable security in random oracle model is proposed.This scheme requires only a bilinear pairing operation in the initial phase of the system and verify the stage,without the need to calculate in the signature phase.The results show that the scheme has higher computational efficiency and communication efficiency than previous certificateless signature scheme.2.Based on the CDH hard problem,a new certificateless aggregated signature scheme is proposed.In the random oracle model to prove that the scheme against adaptive chosen message attack is existentially unforgeable without forking lemma,and this scheme has fast signature verification algorithm and fast transmission efficiency,suitable for application in broadband network environment,the limited storage and computing resources.