MediCon: A Lightweight, Reputation-Based Consensus Protocol to Allow Scalable and Secure Data Sharing in Healthcare

Abstract

Blockchain adds more value to healthcare since its tools emerge as an increasingly popular way to secure, transparently, and tamper-proof sensitive medical records. Nevertheless, current consensus algorithms (i.e., Proof of Work (PoW), Proof of Stake (PoS), and Practical Byzantine Fault Tolerance (PBFT)) use a lot of energy, have latency issues and are not scalable enough or clinically context-aware, which makes them in applicable to healthcare settings. Due to the lack of efficiency of existing solutions, a new lightweight consensus algorithm dedicated to decentralized healthcare systems is proposed, MediCon, in this paper. MediCon incorporates domain-sensitive capabilities, including a Reputation Score (R) where candidates are punished based on their behavior as validators, an Urgency Index (U) that places making progress in clinical transactions in priority, a Committee Rotation Interval (CRI) that maintains dilution of the committee, and a Weighted Voting (WV) system that combines urgency with institutional credibility. Architecture can be summarized as Patient Data Nodes, an Access Layer that is used to provide consent and emergency overrides, Consensus Nodes that are chosen through trust metrics, and a MediCon Core that is used to parse transaction validation. Transactions are put in order of urgency and sensitivity, and then the most reputable validator proposes them. The last block is confirmed with weighted voting and signed with dedicated healthcare compliant standards (e.g., HIPAA, FHIR). Experimental evidence on a simulated multi-institutional healthcare network shows that MediCon leads to latency, throughput, and energy consumption by 48%, 35%, and 60%, respectively, compared to the current consensus models. The similarities in the logic of consensus and clinical priority, as well as trust and patient consent, MediCon provides scalable and secure basis of next-generation healthcare blockchain systems.