Is the Blockchain Useful for Sharing Sensitive Data?

Leakage of sensitive data frequently occurs in network systems. If the secret key is leaked, the original data can be also leaked even if sensitive data are encrypted. In this study, we propose a secure data-sharing framework in which the authorization and authentication for accessing sensitive data are automatically combined together by smart contracts. Through the above combination, the framework prevents access to sensitive data even if the private key is leaked. Therefore, our blockchain-based framework is effective for securely sharing sensitive data.