Towards secure data sharing in cloud computing using attribute based proxy re-encryption with keyword search

Cloud computing plays a significant role in big data era since it can provide dynamic, scalable virtual resource services via the Internet. However, how to enhance the security level of cloud computing is a challenging issue which is urgently to be tackled. In this paper, we center on the data security in cloud computing and present an attribute based proxy re-encryption scheme with keyword search (ABPRE-KS) to provide flexible and secure data sharing among users in the cloud. In our scheme, a user's access privileges are described by an access structure consisting of several attributes while ciphertexts are labeled by several target attributes. A delegator can transform the original ciphertexts into proxy ciphertexts encrypted by the delegatee's attributes without leaking any sensitive information to the cloud server. Besides, a search request on the ciphertexts is allowed by a delegatee if his credentials satisfy the delegatee's access policy. By security analysis, our ABPRE-KS is confidential and keyword semantic secure under BDBH assumption.