Research On Security Technology Of EHR Sharing System Based On Attribute In Hybrid Cloud Environment

Recently, with the rapid development of cloud computing, electronic health record(EHR) is becoming a hot research topic gradually. In this paper, we carried out a research on the EHR sharing system in the hybrid cloud environment. First, a data dividing storage mechanism was proposed to take full advantage of the storage resources in hybrid cloud environments. In addition, in order to achieve the efficient, flexible and fine-grained access control and protect the privacy of user’s information, a privacy preserving decentralized multi-authority attribute-based encryption(PPDMA-ABE) scheme was proposed. Finally, an EHR sharing system in the hybrid cloud environment was established with the above two mechanisms applied. The main achievements are as follows:(1) A data dividing storage mechanism was proposed under the hybrid cloud environments. The data was divided into blocks according to the security and size; an evaluation model of performance was proposed to evaluate public cloud servers; based on the evaluation results and segmentation results, the data was encrypted and stored in the hybrid cloud, given the global data distribution view in hybrid cloud.(2) A decentralized multi-authority attribute-based encryption scheme with attribute revocation and privacy preserving(PPDMA-ABE) was proposed. It achieved flexible access control and privacy of user’s GID without the coordination of CA; In addition, proxy re-encryption technology was used to achieve the revocation of the user’s disabled attributes. The load of the attribute encryption system was reduced with the help of the agent attribute revocation system, while ensuring the confidentiality of user’s data on the agent system at the same time. A standard security model was established to prove that the proposed PPDMA-ABE program reached IND-CPA secure.(3) The data dividing storage mechanism and the PPDMA-ABE algorithm were implemented in the EHR sharing system under Hybrid cloud environment, demonstrating the efficiency and feasibility of PPDMA-ABE through simulation experiments.