Analysis And Research On I Dentity And Certificateless Signature Scheme

With the fast development of information technology,the importance and necessary for the Network Information Security are improving drastically.Digital signature technology acted as a core technologies in the field of the Network Information Security can support the services including identity authentication,data integrity protection,and data non-repudiation during the electronic data transmission.However,the traditional digital signature system has been unable to meet the application requirements of users in different scenarios due to its complicated key management and other issues.Therefore,designing a digital signature scheme with special properties has become a hot research direction in the field of cryptography.In the arena of public key cryptosystem,the identity-based public key cryptosystem not only efficiently solves a serious of problem such as information integrity,confidentiality and non-repudiation and so on in the practical applications,but also successfully avoids the key management problem in the traditional public key cryptosystem.In addition,the certificateless cryptosystem can resolve the key escrow problem in the identity-based public key cryptosystem.This thesis conducts the following research on the identity proxy re-signing and certificateless aggregate signature schemes:(1)In order to solve the problem that the identity-based proxy re-signing scheme does not support user revocation,a revocable identity-based proxy re-signing system is introduced,and the corresponding formal definition and security model are given.Based on the KUNode algorithm,a revocable identity proxy re-signing scheme is designed.In this scheme,the user's signature key consists of two parts:the secret key and the update key.The secret key transmitted through the secure channel is fixed,but the update key broadcast using the public channel changes periodically.Only users who have not been revoked can obtain the update key,and randomize the secret key and update key to generate the signature key for the current time period.The analysis results show that the new scheme efficiently realizes user revocation and key update,and has good scalability.(2)The certificateless aggregate signature system combines the advantages of the certificateless cryptosystem and the aggregate signature system.It has lower computational overhead and communication overhead,and is very suitable for network environments with limited bandwidth,storage,and computing resources.Through the security analysis of the three existing certificateless aggregate signature schemes,it is found that these schemes cannot resist the joint attack of internal signers.To solve this problem,a certificateless aggregation signature scheme against collusion attacks is proposed,whose security depends on the anti-collision of the function.