A SECURE ANTI-COLLUSION DATA SHARING SCHEME FOR DYNAMIC GROUPS IN THE CLOUD

Cloud computing is used to achieve an effective and economical approach for data sharing among group members with the characters of low maintenance and little management cost. Sharing data while providing privacy-preserving is still a challenging issue, especially for an entrusted cloud due to the collusion attack. First, a secured way for key distribution without any secure communication channels is created. Second, can achieve fine-grained access control. Third, we can protect the scheme from collusion attack. Finally, fine efficiency is achieved which means previous users need not to update their private keys for the situation either a new user joins in the group or a user is revoked from the group.