Delay Analysis of Physical Layer Key Generation in Dynamic Roadside-to-Vehicle Networks

Abstract-Secret key generation by extracting the shared randomness in wireless fading channel is a promising way to ensure wireless communication security. Previous works only consider key generation in static networks, but real-world key establishments are usually dynamic. In this work, for the first time we investigate the pairwise key generation in dynamic wireless networks with a center node and random arrival users (eg. road side units with vehicles). We establish the key generation model for this kind of networks. We propose a method based on discrete Markov chain to calculate the average time a user will spend on waiting and completing the key generation (average key generation delay, AKGD). Our method can tackle both serial and parallel key generation scheduling under various conditions. We propose a novel scheduling method, which exploits wireless broadcast characteristic to reduce AKGD and probing energy. We conduct extensive simulations to show the effectiveness of our model and method. The analytical and simulation results match to each other.