Abstract: Data sharing paradigm in distributed systems such as Social Networks and Cloud Computing, there is an increasing demand for distributed data security in the recent adoption and diffusion. The most challenging issue in data sharing is the enforcement of access policies. In this Cipher text Policy Attribute-Based Encryption (CP-ABE) is a promising cryptographic solution for this issue. This allows data owners to define their own access policies over user attribute and enforce the policies on data that is to be distributed. The major drawback with this is Key escrow problem. The key generation canter (KGC) will decrypt any message addressed to a specific user by generating their private keys. This is not a good scenario because the data owners want to be accessed to only specific users. We propose a CP-ABE scheme for data sharing, which allows the key escrow problem would be solved. The security and performance indicates that the proposed scheme is efficient and secure the data distributed.

Keywords: Data sharing, attribute-based encryption, key escrow, access policies.