Cloud-based electronic health record system supporting fuzzy keyword search

As cloud computing becomes prevalent, electronic health record (EHR) system has appeared in the form of patient centric, in which more and more sensitive information from patients is being uploaded into the cloud. To protect patients' privacy, sensitive EHR information has to be encrypted before outsourcing. However, this makes effective data utilization, such as fuzzy keyword search and data sharing, a very challenging problem. In this paper, aiming at allowing for securely storing, sharing and effectively utilizing the EHR, a new cloud-based EHR system is proposed. A binary tree is utilized to store the encrypted records in the proposed scheme, and an attribute-based encryption scheme is applied to encrypt the secret keys. The proposed system is very efficient because only symmetric encryption is introduced to encrypt the records. To support effectively retrieve patients' records, an efficient fuzzy keyword search over encrypted data is proposed without reliance on heavy cryptographic operations, which greatly enhances system usability by returning the matching files. With rigorous security analysis, we show that the proposed scheme is secure, while it realized privacy-preserving data sharing and fuzzy keyword search. Extensive experimental results illustrate the efficiency of the proposed solution.