Efficient Certificateless Authenticated Key Agreement for Blockchain-Enabled Internet of Medical Things

Internet of Medical Things (IoMT) plays an essential role in collecting and managing personal medical data. In recent years, blockchain technology has put power in traditional IoMT systems for data sharing between different medical institutions and improved the utilization of medical data. However, some problems in the information transfer process between wireless medical devices and mobile medical apps, such as information leakage and privacy disclosure. This paper first designs a cross-device key agreement model for blockchain-enabled IoMT. This model can establish a key agreement mechanism for secure medical data sharing. Meanwhile, a certificateless authenticated key agreement (KA) protocol has been proposed to strengthen the information transfer security in the cross-device key agreement model. The proposed KA protocol only requires one exchange of messages between the two parties, which can improve the protocol execution efficiency. Then, any unauthorized tampering of the transmitted signed message sent by the sender can be detected by the receiver, so this can guarantee the success of the establishment of a session key between the strange entities. The blockchain ledger can ensure that the medical data cannot be tampered with, and the certificateless mechanism can weaken the key escrow problem. Moreover, the security proof and performance analysis are given, which show that the proposed model and KA protocol are more secure and efficient than other schemes in similar literature.