# A Blockchain-Based Secure Inter-Hospital EMR Sharing System  
[PERSON]  
1 College of Computer and Information Engineering, Xiamen University of Technology, Xiamen 361024, China; [EMAIL_ADDRESS] (C.-L.C. ); [EMAIL_ADDRESS] (M.Z. )1 College of Computer and Information Engineering, Xiamen University of Technology, Xiamen 361024, China; [EMAIL_ADDRESS] (C.-L.C. ); [EMAIL_ADDRESS] (M.Z. )1 College of Computer and Information Engineering, Xiamen University of Technology, Xiamen 361024, China; [EMAIL_ADDRESS] (C.-L.C. ); [EMAIL_ADDRESS] (M.Z. )1 College of Information Engineering, Changchun Sci-Tech University, Changchun 130600, China; clc@mail. At the same time, with the growth of medical technology, medical information is becoming increasingly important in terms of patient identity background, medical payment records, and medical history. In the past, medical records were transmitted through paper, and with the development of technology, these medical records were electronically stored in private servers in hospitals [11; 12; 13; 14; 15]. Medical information can be the most private information about a person, but due to issues such as operation errors within the network or a hacking attack by a malicious person, there have been major leaks of sensitive personal information in the past [16; 17; 18; 19; 20]. In any case, this has become an issue worth studying in order to ensure the privacy of patients and protect these medical materials. On the other hand, under the current medical system, the patient's medical record cannot be searched across the hospital. For example, when a patient is originally diagnosed and treated in hospital A, and then visits hospital B, hospital B must perform the same examination again, resulting in a waste of medical resources. Furthermore, when a patient seeks medical treatment, the physician does not know the medical history of the patient relating to other hospital visits in the past, and this also increases the medical risk and reduces the accuracy of the diagnosis [21; 22; 23; 24; 25]. Therefore, inter-hospital medical record access is a very important goal. Besides this, blockchain-related technologies and applications have gradually emerged in recent years [26; 27; 28; 29; 30]. Blockchain technology is essentially a decentralized database maintained by the collective. It has the characteristics of high reliability and high confidentiality and has the strong prospect of effectively solving the trust problem between the two parties. Credit is the basis for the production and maintenance of social relations between people and organizations. At present, people mainly use regulations, systems, laws, contractual agreements, etc. to restrict credit problems. These methods cannot solve credit problems because of many subjective factors. The decentralization of the blockchain allows all users who join the blockchain to participate in the data authenticity proof, abandoning the shortcomings of the traditional certification system, the single certification center [31; 32; 33; 34]. According to the WHO (World Health Organization) forum [35], the emergence of blockchain technology has provided solutions for medical resource management in recent days. Blockchain technology allows hospitals, patients, and other parties to share data within the blockchain, without worrying about the security and integrity of the data [36; 37; 38]. Through smart contracts, patients can authorize medical staff to access their medical information, so that medical staff can understand this information and provide better care services. Moreover, through blockchain technology, the patient's EMR (electronic medical record) is directly obtained from the server of the original hospital, so the content of the EMR will not be limited to a specific format. Compared with the current EMR sharing mode [39; 40], better integrity and timeliness can be achieved with this method.