Efficient Blockchain-Based Electronic Medical Record Sharing With Anti-Malicious Propagation

Electronic Medical Records (EMRs) sharing enhances healthcare and biomedical discoveries but faces challenges: data provider centralization and limited interoperability. Blockchain can address these issues, but existing systems struggle with malicious EMR propagation due to challenges concerning the authenticity, non-repudiation, and integrity of the digital signatures they employ. Universal Designated Verifier Signature Proof (UDVSP) may be an intuitive solution, but existing UDVSP schemes are inefficient due to time-consuming bilinear pairing operations. In this article, we first adopt the Elliptic Curve Digital Signature Algorithm (ECDSA) to propose a more efficient and blockchain-friendly UDVSP scheme, following by a blockchain-based EMR sharing system (EMRChain). To our best knowledge, our proposed UDVSP scheme is the first bilinear pairing-free solution, and EMRChain is the first blockchain-based EMR sharing system to possess the anti-malicious propagation. Furthermore, we proceed to provide a thorough security analysis and performance evaluation of both our UDVSP scheme and EMRChain. Our UDVSP scheme is provably secure within the security model and offers significant computational cost savings (at least 86.76%) and reduced communication overhead (at least 59.37%) compared to existing UDVSP schemes. These results, along with the EMRChain prototype, effectively showcase the utility and effectiveness of EMRChain, which is built upon our UDVSP scheme.