Research On Identity Authentication Technology Based On Blockchain And Signcryption

Internet users can share the resources of servers and communicate and exchange data with other users.However,the Internet network environment is complex,with many types of data and various security issues,including an overly simple authentication system for users and a lack of proper integrity and privacy protection for data.The application of identity-based cryptosystem can simplify the key management;the sign-encryption technology can realize both digital signature and encryption functions in one logical step,which can realize both privacy protection and identity authentication;the trustworthy,open and transparent,tamper-evident and traceable characteristics of blockchain can also protect the privacy and integrity of information;the consensus mechanism can enable nodes to reach unanimity.Therefore,combining the above technologies,designing an identity authentication system based on blockchain and sign-encryption technology can meet the needs of identity authentication and privacy protection in network communication.The main work of this thesis research is as follows.1.To address the problems of complex signature steps and low efficiency in blockchain consensus,this paper improves on the basis of threshold ring signature and proposes Aggregate Threshold Ring Signature(ATRS).This algorithm takes advantage of the efficiency and anonymity of the threshold ring signature and adds the feature of the aggregate signature,which reduce the computational cost by aggregating the signatures generated by all nodes in the threshold ring signature scheme into a short signature.This algorithm can be proved correct by verifying the short signature.Finally,this scheme effectively reduces the steps of signing and verification and improves the efficiency of signing.2.To address the problems that traditional consensus mechanism has too many information interactions and simple election strategy of master node,this paper combines the proposed Aggregate Threshold Ring Signature(ATRS)algorithm,which is efficient,anonymous and takes up less space,and applies it to the consensus mechanism of blockchain,then proposes a consensus mechanism based on ATRS algorithm,named Ring Signature-Practical Byzantine Fault Tolerance(ATRS-PBFT)consensus mechanism.This consensus mechanism reduces the number of signatures and verifications and improves the efficiency of the mechanism.In order to increase the security,the consensus proposed in this paper also adopts a credit hierarchy in the master node election strategy,divides the nodes' credit rating before the master node election,and selects the nodes with high credit rating as the master nodes,which reduces the probability of malicious nodes becoming the master nodes.The optimized consensus mechanism can both achieve privacy protection for nodes using ring signature and reduce the data computation in the signature process to improve the efficiency of the mechanism.From the simulation experiments,it can be seen that ATRS-PBFT consensus has the advantages of increased throughput,reduced latency,short block-out time,and high efficiency compared with the traditional PBFT consensus mechanism.3.To address the problems of information theft,tampering and identity theft in insecure communication networks,users need to protect privacy information and verify user identity simultaneously when participating in Internet communication and data transmission.Based on the traditional identity authentication mechanism,we propose a identity authentication scheme based on blockchain and signcryption,which enables secure storage and sharing of identity information in the blockchain when users with identity information and the platform interact with information in the system.The overall scheme is divided into four stages: system initialization,appointment,storage in the blockchain and access to the blockchain,with the characteristics of confidentiality,unforgeability,verifiability,privacy protection and non-tamperability.In the environment of standard model,the scheme we proposed can prove its security,unforgeability,privacy and verifiability.The performance analysis of communication overhead and computation overhead shows that compared with previous authentication schemes,this paper's scheme is suitable for practical scenarios with increased functionality,brief time for signcrypting and designcrypting secrets and it increased efficiency with reduced communication cost.