Research On Threshold Group Signature Scheme In Blockchain Mode

Threshold group signatures,as one of digital signatures with special properties,play an important role in identity authentication,prevention of forgery and non-repudiation,anonymity and so on.In addition,blockchain as a kind of decentralized,tamper-resistant,traceability,jointly safeguard of distributed database,its application extends from the original digital currency to many intelligent fields such as the Internet of Things.people have begun to study new threshold group signature schemes suitable for blockchain to store data.This paper focuses on the threshold group signature scheme and its application.The main research contents are as follows:(1)Proposing a threshold group signature scheme which verifiable key sharing base on Blockchain.It combined with the decentralized and tamper-resistant features of block chain technology,and used the verifiable key sharing technology to solve the problem of member private key leakage.By using elliptic curve cryptosystem,it can achieve the effect of shorter key and higher security.The signature synthesizer is used to encrypt the membership information to ensure the anonymity of signature members.The analysis results show that the scheme can not only resist forgery attack of signature and joint attack of member,but also it has lower calculation and communication.Scheme can be effectively adapted to the project completion acceptance scene,it has strong theoretical significance and practical application value.(2)Proposing a threshold group signature scheme for Medical Consortium.It is combined with blockchain technology to solve the trust problem between multiple parties,using the Asmuth-Bloom algorithm has characteristics of small computational complexity and high efficiency to reduces the complexity of key generation,utilizing the method of sharing the respective sub-key to avoid the authoritative deception of the trusted center,using the fuzzy processing of the node identity to realize the privacy protection of the node,using the validity verification of the share signature to prevent malicious deception among the members and conflict tracking is realized by the management of the node joining process.Security analysis shows that the scheme satisfies security features such as unforgeability,anonymity,and traceability.Performance analysis shows that under the same level of computational complexity,the scheme is more secure and can be better adapted to the medical environment.