Data sharing is an important functionality in cloud environment. With the advent of the World Wide Web and the emergence of e-commerce applications and social networks, organizations across the world generate a large amount of data daily. This data would be more useful to cooperating organizations if they were able to share their data. In this article, an efficient methodology is provided to securely, efficiently, and flexibly share data with others in cloud computing. In this technique, the secret key holder can release a constant-size aggregate key for flexible choices of cipher-text set in cloud storage, but the other encrypted files outside the set remain confidential. Secure cryptographic architecture and working methodology are proposed in this paper for optimal services over the cloud.

cloud computing, data sharing, decryption, encryption