Preserving Forward Security Authentication with User Revocation

Abstract

Cloud computing provides many services and also convenient ways of data sharing. Data in the cloud can be accessed by an individual or shared among the group and since the data often contains valuable information, security of the data plays a crucial role. Several security mechanisms have been proposed for secure data sharing .This paper reviews some security mechanism which is Identity-based (ID-based) ring signature with user revocation. Ring signature is a promising candidate to construct an anonymous and authentic data sharing system. It allows a data owner to anonymously authenticate his data which can be put into the cloud for storage or analysis purpose. Yet the costly certificate verification in the traditional public key infrastructure (PKI) setting becomes a bottleneck for this solution to be scalable. Identity-based (ID-based) ring signature, which eliminates the process of certificate verification, can be used instead. our proposed scheme can achieve fine-grained access control, upon compromised of key of a data owner, he uses forward security mechanism which validates the past signature even if the current secret key is compromised, any user in the same group can use the source in the cloud and revoked users cannot access the cloud again after they are revoked.