Reinforce cloud computing access control with key policy attribute-based anonymous proxy reencryption

Cloud computing is an emerging paradigm that provide technology and computer resources as a service. However due to data outsourcing and untrusted cloud servers, the data privacy and data access control becomes a challenging issues in cloud computing. In this paper, we propose a fine-grained access control system using a combination of key-policy attribute-based encryption system and an anonymous proxy reencryption, this proposed scheme is an efficient model that enforcing access policies based on data attributes, allowing the delegation of computation implicated in fine-grained access control to untrusted cloud servers without disclosing the data content. Previous schemes that use (KP-ABE) and proxy reencryption, leave how to be secure against chosen-cipher-text attacks (CCAs) as an open problem. The new scheme supports attribute-based encryption with anonymous proxy re-encryption. Our scheme is CCA secure, and secret key security is guaranteed, which is not provided by the current work.