An Inner Product Predicate-Based Medical Data-Sharing and Privacy Protection System

Abstract

Searchable encryption is widely used in electronic health record systems because it enables users to search ciphertext data without decryption. However, the existing traditional searchable encryption schemes lack fine-grained access policies with wildcards in electronic health record systems. And they also do not consider the problem of hiding policies, as well as the problem of incomplete search results caused by cloud servers. In order to solve all the above problems, this paper proposes a blockchain-aided attribute-based searchable scheme with the properties of inner product predicate. In the proposed scheme, the attribute encryption mechanism implements fine-grained access policies with wildcards, which improves the data owner's ability to control access authorization precisely. Introducing the inner product predicate not only achieves fully hidden access policies but also prevents the leakage of sensitive medical data. The immutability of the blockchain ensures the integrity of multi-keyword search results, guaranteeing reliable data sharing. Finally, the security proof and the performance evaluation are conducted to confirm the security and effectiveness of the proposed scheme.INDEX TERMS Attribute-based searchable encryption, Fine-grained access policies with wildcards, Fully hidden, Inner-product predicate, Blockchain. I. INTRODUCTION A. BACKGROUND VOLUME 11, 2023