Research On Two Kinds Of Digital Signature Schemes With Special Properties

The rapid development of modern communication technology has provided people with a variety of information acquisition and transmission channels.At the same time,people's daily lives are flooded with a large number of fraudulent information.How to ensure the reliability of information transmission and the authenticity of information obtained is an urgent issue to be solved in the era of information explosion.The digital signature technology in cryptography has the functions of verifying the integrity of information,realizing source authentication and preventing repudiation,and can effectively solve the above problems.However,with the rapid development of e-commerce and e-government services,ordinary digital signature schemes cannot meet security requirements in certain specific application environments such as electronic voting,anonymous reporting,and batch verification of data.Therefore,digital signature with special properties will usher in a broad application prospect.Through a large number of studies on aggregate signatures and partially blind signatures,the following research results were mainly achieved.(1)The traditional signature scheme requires the verifier to verify each signature one by one,resulting in its large overhead and low efficiency.Aggregate signature can achieve batch verification of multiple signatures and save time.In this paper,a new certificateless aggregate signature scheme is proposed.The new scheme initiates a signature protocol through a specified aggregator.In addition,state information including random numbers is introduced in the scheme so that each round of aggregate signatures generates different state information.Compared with the existing schemes,the proposed scheme reduces the computation overhead on the basis of provable security.(2)In electronic voting,electronic payment and other systems,in order to achieve the protection of the user's privacy while also being able to trace the user's identity when it is necessary,researchers have proposed the concept of partially blind signature.However,the current identity-based partially blind signature schemes generally have the problem that the public information is replaced.Through the analysis of the security of the Liu's scheme,it is pointed out that the user can modify the public information illegally.To solve this problem,a modified scheme of partially blind signature based on ID is proposed.The new scheme doesn't use the bilinear pairing which has higher computational cost,and overcomes the defect of public information being tampered with.Compared with the existing schemes,it has significantly improved the security and efficiency.(3)Partially blind signature is designed to solve the contradiction between anonymity and controllability.Through the analysis of the security of the He's scheme,it is pointed out that the public information can be illegally modified when the signer is unaware of it.To solve this problem,we propose an efficient ID-based partially blind signature scheme combined with He's scheme and Tang's scheme.Compared with the existing schemes,our scheme not only decreases the computation cost but also prevents public information which has been tampered.