Key agreement in wireless sensor network Authors: Min-Shiang Hwang and Yung-Chih Lu

Introduction Connectivity ratio Resiliency Overhead Rekeying Authentication Blind signature

Group polynomial-based scheme (1/3) Theorem Setup server randomly generates a symmetric multivariate t- degree polynomial Example: It’s a symmetric multivariate 3-degree polynomial

Group polynomial-based scheme (2/3) Key agreement Step1: computes 1: H-sensor’s ID 2: Lu-sensor’s ID 3: Lv-sensor’s ID Step2: The Setup server loads the sensor node with coefficients Setup Server (Base Staton) distribution :Lu-sensor :H-sensor :Lv-sensor L-sensor: Low-end sensor s: Step H-sensor: Cluster head

Group polynomial-based scheme (3/3) Key agreement Step3: Each sensor node broadcasts its own ID Step4: Receivers use ID to compute a shared secret conference key K=f(1,2,3)=f(1,3,2)=f(2,1,3)=f(2,3,1)=f(3,1,2)=f(3,2,1)=1387 :H-sensor :Lu-sensor :Lv-sensor L-sensor: Low-end sensor s: Step H-sensor: Cluster head

Group polynomial-based scheme2 (1/3)

Group polynomial-based scheme2 (2/3) Symmetric Polynomial Generation Phase :H-sensor :Lu-sensor :Lv-sensor