Electronic Health Record Sharing Scheme With Searchable Attribute-Based Encryption on Blockchain

With the digitization of traditional medical records, medical institutions encounter difficult problems, such as electronic health record storage and sharing. Patients and doctors spend considerable time querying the required data when accessing electronic health records, but the obtained data are not necessarily correct, and access is sometimes restricted. On this basis, this study proposes a medical data sharing scheme based on permissioned blockchains, which use ciphertext-based attribute encryption to ensure data confidentiality and access control of medical data. Under premise of ensuring patient identity privacy, a polynomial equation is used to achieve an arbitrary connection of keywords, and then blockchain technology is combined. In addition, the proposed scheme has keyword-indistinguishability against adaptive chosen keyword attacks under the random oracle model. Analysis shows that the scheme has high retrieval efficiency.