Optimal secret sharing for wireless information security in the era of Internet of Things

Abstract

Secret sharing is crucial to information security in wireless communications in the era of Internet of Things. In this paper, we study how to optimally share secrets between two and more users using the effect of wireless channel dynamics on the data link layer. For the two-user case, we formulate an optimization problem whose objective is to minimize the expectation of the probability that an eavesdropper receives all secret sharing packets. Our contributions are as follows: (i) we come up with the secret sharing mechanism that minimizes the aforementioned objective function and (ii) we perform analysis on our approach and derive the worst-case probability of the eavesdropper receiving all secret sharing packets. For the multi-user case, we focus on the scenario that three users within each other’s communication range try to establish a common secret. A novel multi-user secret sharing mechanism that allows all three users to contribute toward the common secret is developed and analyzed. Our approach has two nice properties: (i) it is able to reset itself in case of packet transmission error and (ii) its secret sharing efficiency is high when the probability of packet transmission success is not low. Our results are validated via simulations.