Abstract:

In order to ensure the reliable and stable operation of the railway system and improve the safety protection capability of the railway time synchronization network, CPN was used to analyze the safety of the identity authentication of the railway time synchronization network. Firstly, based on the Autokey model of the time synchronization protocol authentication process, the CPN model of the challenge-response identity authentication process based on public parameters was established. At the same time, this model was used to analyze the possible vulnerabilities of the challenge-response mechanism based on common parameters. Secondly, a CPN model of the challenge-response process under the man-in-middle attack was established. The state equation of the model was established by using the reverse state analysis method to analyze the reachability of the insecure state of the identity authentication protocol. Finally, the safety analysis results were simulated and verified by CPN Tools. The results show that the CPN model analyzes that there are safety vulnerabilities in the process of challenge-response authentication in the railway time synchronization network, and the client lacks the verification of the source information of the challenge-response packet. As a result, the forged challenge-response packet can be authenticated by the client to achieve the purpose of manipulating the time node. The model deduces the man-in-middle attack sequence, which provides an important reference for the safety protection strategy of the railway time synchronization network.

Key words: railway time synchronization network, challenge-response, identity authentication, safety analysis, colored Petri nets(CPN), man-in-middle attack