This document proposes a novel approach for secure group data sharing and storage in cloud computing. It aims to enable anonymous data sharing within a group in the cloud with high security and efficiency. The approach uses group signatures and key agreement to allow group members to secretly share data about the group, while a common group key is determined based on key agreement to allow secure sharing and storage of group data in the cloud. Both theoretical and experimental analysis show that the proposed scheme is secure and efficient for group data sharing in cloud computing.