Research On Identity-based Key Isolation Group Signature Scheme

Social development drives the development of network technology,they usually use password to protected information exchange in many areas.Digital signature has been widely used in many fields,which replaces the traditional handwriting signature.With the change of the application environment,some common digital signature can't meet the needs of development,so some digital signatures with specific functions that can adapt to complex environments have emerged.As one of them,group signature have been widely used in auctions,electronic voting and other fields which based on group signature's excellent properties of anonymity and traceability.For a cryptosystem,it is generally composed of a key and a public algorithm.Because the algorithm is usually an open and difficult problem,so the security of the entire cryptosystem is determined by whether the key is secure.However,the leakage of the key is unavoidable in a complex network environment.In order to reduce the damage that the key leakage may cause,the researchers have proposed three solutions,which include forward secure technology,key isolation technology and intrusion tolerance technology.There also may cause key leakage problem in the identity-based group signature scheme.The researcher use the forward security to solve this problem,but the forward security technology can only guarantee the signature security before the key is leaked and not guarantee the security of the signature after the key disclosure.The scheme also have some shortcomings such as long signature length and complex construction process and so on.Regarding the issue above,we use the key isolation technology combined with the group signature scheme and proposes the concept of the identity-based key isolation group signature scheme for the first time in this paper.Finally,we construct a concrete implementation scheme.The scheme makes full use of the advantages of key isolation,even if the scheme's key is disclosure,which does not affect the security of the time period before the key is compromised and the security of the time period after the key disclosure.It greatly reducing the harm caused by the key disclosure.We make full use of the better characteristics of bilinear pairings to construct a secure group signature scheme that satisfies key isolation in this paper.The signature length is shorter and can be applied in a bandwidth-constrained environment,the construction process is simple and there is no fixed life cycle.