의료 데이터 공유를 위한 블록체인 기반의 무결성 보장 및 프라이버시 보호와 사용사례 구현

Abstract

In general, the center of the medical institution operates the medical information system. In most current systems, the medical data are stored in the provider database, so that the patients do not have full access rights to manage the data. Moreover, the problem is augmented if the medical data is fragmented into several medical institutions. Whenever a dispute occurs between the medical institution and patient, the institution cannot use patient's medical data as evidence to judge the appropriateness of medical treatment because the patient has no way to prove it. As a solution, we can use the blockchain to determine the integrity of medical data. However, the nature of blockchain gives the privacy problems for the patients due to blockchain stores the data publicly in the network. In this sense, every party in the network allows viewing the transaction as well as the patient record. Public data is contrary to the nature of medical data which is sensitive to each party. To address the problem, we use the stealth address protocol to disguise the identity of the parties. In this thesis, we implement the smart contract as an escrow to enable fairness sales of medical data. A payee enables to sell medical data to the payer safely with a guarantee that the payer will pay comㅈpensation and the payee will send the corresponding medical data. To do so, the payer needs to deposit the coins (cryptocurrency) to the smart contract. If all procedures are met, the smart contract shows the IPFS address which is the links to access the data. By leveraging this model, we solve the privacy issue of the patient's identity. Based on our evaluation, the smart contract produces a reasonable gas cost for every transaction. Therefore, this smart contract is usable in a practical environment.