RCME: A Reputation Incentive Committee Consensus-Based for Matchmaking Encryption in IoT Healthcare

Matchmaking encryption is a method employed to address the security and privacy concerns of cloud-enabled IoT healthcare. Nevertheless, matchmaking encryption technology encounters challenges in effectively implementing critical functionalities, such as resolving a single-key-exposure problem, achieving secure short-epoch communication, and simultaneously enabling lightweight computation and communication overheads for IoT healthcare. These challenges pose obstacles to the widespread adoption of this technology. To tackle these constraints, we first present a R eputation incentive committee C onsensus-based for M atchmaking E ncryption in IoT healthcare (RCME), which utilizes consensus nodes to eliminate the single-key-exposure problem and enables fast provision of permission proof based on our design reputation incentive mechanism. The proposed RCME scheme adopts low-consumption pairing-free technology to realize lightweight matchmaking encryption in a multi-party, non-interactive certificateless cryptosystem. Rigorous security analysis shows it achieves chosen ciphertext attack security under the random oracle model. To further reduce consensus communication overhead from <tex-math notation="LaTeX">O(n²)</tex-math> to <tex-math notation="LaTeX">O(n)</tex-math> , we propose an optimized Practical Byzantine Fault Tolerance (PBFT) consensus, and we adopt reputation incentive mechanism and threshold cryptography technology to achieve unbiased leader election. The comprehensive evaluation corroborates that our solutions outperform the existing state-of-the-art schemes regarding security and performance. Therefore, our RCME scheme is a practical solution for resource-constrained IoT healthcare devices.