Authenticated Dynamic Group Key Mechanism for Data Sharing in the Cloud

Abstract

Authenticated dynamic group key mechanism for data sharing designs a secure data sharing data in an untrusted cloud. A user is able to share data with others in the group without revealing identity privacy to the cloud. Additionally it supports efficient user revocation and a new user joining. More specially, efficient user revocation can be achieved through a public revocation list without updating the private keys of the remaining users, and new users can directly decrypt files stored in the cloud before their participation. Moreover, the storage overhead and the encryption computation cost are constant. Extensive analyses show that proposed scheme satisfies the desired security requirements and guarantees efficiency as well.