Miner Selection in an Internet of Medical Things Framework using Fuzzy Logic

Blockchain-enabled Internet of Medical Things (IoMT) is a secure, transparent, and decentralized network of medical devices which facilitates a patient-centric healthcare system for distributed exchange and management of medical records. The existing consensus protocols designed for a blockchain network such as Proof-of-Work, Proof-of-Stake, Proof-of-Negotiation, Proof-of-Authority, and Proof-of-X-Repute lack fast processing and security. This paper presents a scalable blockchain-enabled IoMT framework that uses gateway nodes to improve the performance. A novel hybrid consensus mechanism namely Proof-of-Context (PoCt) is also proposed for blockchain-enabled IoMT environment. The proposed PoCt consensus is a fast, reliable, and secure mechanism for block mining which consists of a fuzzy-based miner selection and a block validation process with multiple parameters. Fuzzy-based miner selection is done on the basis of context factor of a node, which is computed using the impact score, vote count and trust value. The trusted miner nodes are responsible for block generation and validation. The most trusted and efficient miner node having the highest neighbour density is being selected for block generation. The other miner nodes are responsible for block validation to prevent various malicious activities. The performance analysis of the PoCt consensus shows that it is comparatively 24% more efficient, 36% faster, 1.8% more reliable, and 65% less traffic overhead than fuzzy-based super leader nomination in PoS consensus mechanism, 65% faster than random-voting and game-theory based miner selection, 25% faster than Proof-of-Negotiation consensus, 6.1% more reliable and 58% less traffic overhead than Proof-of-Authority consensus mechanism for the network of 500 nodes. Security analysis of PoCt consensus algorithm ensures its resilience against various known mining attacks.