Abstract: Data storing and sharing is an imperative functionality in distributed networks. We propose a secure and reliable multi-owner data sharing scheme in cloud environment. It implies that any user in the group can securely share data with others in the distributed systems. The proposed scheme is able to support dynamic groups efficiently. Specifically, new granted users can directly decrypt data files uploaded before their participation without contacting with data owners directly. The size and computation overhead of encryption are constant and independent with the number of revoked users.

Keywords: Cloud security, Hybrid Cloud, Attribute Based Encryption, Private Cloud.