Vulnerability Analysis of Clock Synchronization Protocol Using Stochastic Petri Net

With the development of the industrial informatization, the problems of security in field device layer have been gradually exposed, which mainly involves specified industrial communication protocols. Clock synchronization protocol, as one of the most important industrial communication protocols, ensures the real-time performance of industrial control system. Considering that the related researches have not yet formed a mature system, we propose a new method for analyzing the vulnerability of clock synchronization protocol in this article. In this method, SPN(stochastic petri net) is introduced as a modeling tool, while IEEE 1588 PTP clock synchronization protocol is regarded as the research object. An SPN(stochastic petri net) model is strictly built according to the protocol. Then, steady-state probability expressions are obtained by the isomorphic Markov chain. Through changing trigger rate of transitions of several pivotal states which are related to vulnerability, the influences of each parameter has on the model could be quantitatively reflected in the result of simulation in order to analyze vulnerability of clock synchronization protocol by determining the critical factors that affect protocol´s vulnerability.