Heartbeat Based Key Agreement Protocol In Wireless Body Area Networks

Wireless body area networks(WBANs)composed of wearable devices have increasingly become an integral part of personal health monitoring and medical assistance.Due to its sensitivity,the health data transferred among devices carried by a person should be protected from leakage.A series of key agreement schemes using heartbeats as a source of trust have been proposed.However,because of the unrealistic assumption in their threat model and the use of fixed parameters,previous schemes have unstable performance for different individuals and even have the risk of security degradation such that the schemes can be compromised by attackers.In addition,the resource-constrained wearables in the WBANs pose severe challenges to the design of protocol in terms of communication,computing and memory overhead.Thus,the efficiency of the protocol needs to be further improved.In this paper,we design efficient and secure key agreement protocols to solve the problems existing in the previous research work so as to meet the needs of secure communication in WBANs.Firstly,we take into consideration the risk that previous healthy records of the user may be obtained by the attacker through social engineering or some other means.Then we propose two efficient and secure key agreement protocols under directions of key binding and key generation.Key binding uses biometrics to cover key,while key generation uses biometrics to directly generate session key.The protocol under the direction of key binding is based on fuzzy commitment.Through the modeling and analysis of the security strength and the success rate of key negotiation,a physiological-distribution-based parameter optimization(PDPO)algorithm is proposed to adaptively select the optimal protocol parameters for different individuals,which not only brings excellent and stable performance,but also ensures the security.Besides,we prototype the protocol and conduct experiments with multiple subjects to evaluate its security and performance.The results show that the protocol can negotiate the key safely and efficiently,which is suitable for practical applications.the scheme can achieve a success rate of 99.88%,which only consumes 1.508 m J and takes 31.9 ms when negotiating a 79-bit key and the witness strength can reach 136 bits.The protocol under the direction of key generation is based on fuzzy extractor.We construct a robust secure sketch scheme based on Chebyshev distance,which is more secure than previous research work and has lower communication cost.In addition,we conduct a series of experiments.The result shows the protocol is secure and efficient.The performance of the protocol is better than the previous research work,which can achieve a success rate of 98.20%,and the core computation of code only takes 0.361 ms.