A secure blockchain-based e-health records storage and sharing scheme

Due to the expeditious evolution of wearable technology and wireless mobile networks, the tele-medicine and mobile medications have turned up into the Telecare Medicine Information System (TMIS). The efficient management of the patient's Electronic Health Record (EHR) plays a vital role for the telecare of patients that include medication for the chronic patients, long-term telecare for the special patients, analysis of patients infected with certain disease etc. The sharing and distribution of EHRs with medical practitioners can enhance accuracy of the diagnosis; however, privacy and security preservation of patients' record are the detracting issues of this system. Recently, due to the property of immutability, blockchain technology has been introduced to be as an auspicious solution for achieving EHR sharing with privacy and security preservation. This work puts forward a novel blockchain-based privacy and security preserving EHR sharing protocol for improved diagnosis and efficient treatments in TMIS. Firstly, two types of blockchains, named as private blockchain and the consortium block chain, are constructed by formulating their consensus, data structures and mechanisms. Private blockchain is in charge of maintaining EHRs, while consortium blockchain stores EHRs' secure indexes. In order to attain data security, secure search, access control and privacy preservation, all the EHRs are public-key encrypted with appropriate searchable keyword. Security analysis of our protocol validates that our protocol achieves all the security goals by exempting several security attacks. For achieving efficient computational results, the user and server sides of our scheme are implemented separately. Furthermore, performance analysis of our protocol with other existing protocols reveals that our protocol is relatively better in terms of the communication and computation overhead by providing notable level of the security.