Design And Application Of The Threshold Signature Scheme

Along with the emergence of information and the popularity of computer network, digital signature plays a more and more important role in information security. Thus more new requirements have been proposed. In the cryptosystem oriented to group or organization, proper combination of some appointed personnel are required to stand for the signature of the whole group. In order to meet the application demand, threshold signature has been found on the conception of secret sharing, which exhibits the security of risk sharing and power allocation.Once the present threshold signature scheme is conspiratorially attacked, the entire previous signature generated from the group will become invalid. In light of the problem, Chapter 3 founded a verifiable forward security threshold signature scheme based on the digital signature scheme of elliptic curve, which adopted Pedersen verifiable threshold secret sharing technology. Moreover it was testified that the scheme displayed the characteristics of robustness, forward security and forgery resistance, showing a certain theory and application value.Compared to the centralize control network, the distributed network has no definite trusted center. Thus a dynamic certificate authority is required to provide authentication service for new members. The model of authentication service based on threshold signature algorithm can resolve the above problem. Based on a strong RSA threshold signature scheme, Chapter 4 founded a distributed authentication service model without center node, including system initiation, certification issue and repeal together with certification authority. Compared to the present scheme, it shows easier realization and higher security.