Location-Based Key Management Strong Against Insider Threats in Wireless Sensor Networks

To achieve secure communications in wireless sensor networks (WSNs), sensor nodes (SNs) must establish secret shared keys with neighboring nodes. Moreover, those keys must be updated by defeating the insider threats of corrupted nodes. In this paper, we propose a location-based key management scheme for WSNs, with special considerations of insider threats. After reviewing existing location-based key management schemes and studying their advantages and disadvantages, we selected location-dependent key management (LDK) as a suitable scheme for our study. To solve a communication interference problem in LDK and similar methods, we have devised a new key revision process that incorporates grid-based location information. We also propose a key establishment process using grid information. Furthermore, we construct key update and revocation processes to effectively resist inside attackers. For analysis, we conducted a rigorous simulation and confirmed that our method can increase connectivity while decreasing the compromise ratio when the minimum number of common keys required for key establishment is high. When there was a corrupted node leveraging insider threats, it was also possible to effectively rekey every SN except for the corrupted node using our method. Finally, the hexagonal deployment of anchor nodes could reduce network costs.