Untraceable blockchain-assisted authentication and key exchange in medical consortiums

Medical consortium provides tamper-proof data sharing of patient medical records. Since the communications of patients’ devices with hospital servers are accomplished through insecure mediums, scholars have suggested secure authentication protocols to protect the communication links. Yet careful analysis of cutting-edge blockchain-assisted schemes reveals they are susceptible to flooding, ephemeral secret leakage, and tracing/tracking attacks. Besides, they cannot provide a proper balance between security and resource efficiency. This paper introduces a blockchain-assisted authentication protocol that not only defends against potential attacks, but also significantly improves efficiency in computation, communication, and storage usage on the blockchain. Besides, patients are able to receive continuous services from multiple hospitals after just one registration on a cloud server, with the blockchain ensuring the authenticity and traceability of authentication records. We present both formal and informal proof of the proposed protocol and conduct experimental evaluations using ARM and Hyperledger Fabric to provide realistic security and performance insights.