Background: A secure, flexible and robust intra-cluster key management framework is
proposed as a general solution to establish the pairwise key between a sensor and its cluster head in
Methods: Based on the classical low-energy key management (LEKM) protocol, this framework
employs the threshold secret sharing in the key pre-distribution and pairwise key establishment phases.
Results: Compared to the LEKM protocol, the framework inherits the low-energy advantage and
improves the flexibility, the robustness, and the resilience against node capture attacks.
Conclusion: Theoretical analysis and simulation prove that this framework has many advantages:
firstly, it improves the security against node capture attack compared to probabilistic schemes;
secondly, it is flexible in key revocation/renewal operations by using the threshold technique; thirdly, it
is robust against CH nodes capture attack, which is achieved by guaranteeing high connectivity after
node recovery. At last, it inherits the energy-efficient property of the LEKM protocol, which is optimal
in saving the energy consumption of low-power sensors.