Hierarchical Key Negotiation Technique for Transitory Master Key Schemes in Wireless Sensor Networks

Wireless sensor networks have been applied in various contexts where hardware and network data are exposed to security threats, such as tampering or eavesdropping. The majority of the security approaches adopted in this context are based on symmetric encryption, which requires keys shared among the nodes. Many key management schemes, like the transitory master key scheme LEAP+, have been proposed for the negotiation of keys. In this paper a new key negotiation technique suitable for LEAP+ protocol is described. The proposed protocol significantly reduces the time of exposition of sensitive information through a new organization of handshake operations and of key establishment. A comparison with the original version of LEAP+ was performed to evaluate the improvements achieved by the proposed approach.