基于TCPN的铁路时间同步网延迟攻击应对策略研究  

Research on Countermeasures Against Delay Attack of Railway Time Synchronization Network Based on TCPN

作　　者：赵庭达 武晓春[1] ZHAO Tingda;WU Xiaochun(School of Automation and Electrical Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学自动化与电气工程学院,兰州730070

出　　处：《铁道标准设计》2022年第8期168-174,共7页Railway Standard Design

基　　金：国家自然科学基金地区项目(51967010)。

摘　　要：铁路时间同步网采用的时间同步协议NTP自身具备一定的安全缺陷,容易受到网络攻击影响。对网络时间协议(NTP)进行分析,使用时间有色Petri网(TCPN)建立NTP对时阶段时间同步过程模型,并对模型进行仿真测试,仿真结果验证了模型的正确性。针对NTP协议延迟攻击,确定攻击产生的时间偏差和引入延迟的关系,分析延迟攻击对铁路时间同步网造成的影响并提出检测思路。根据攻击者引入的延迟与客户端计算偏移量的关系,提出NTP协议延迟攻击的缓解方法,将NTP时间同步过程模型进行扩展,在原模型的基础上加入攻击节点和缓解方法模块,对延迟攻击及其缓解方法进行模拟。经过多组仿真验证,缓解后的主从时间偏移量均小于2ms,提出的缓解模型可有效缓解NTP延迟攻击造成的影响。The Network Time Protocol(NTP) adopted by the railway time synchronization network has certain security vulnerabilities and is vulnerable to network attacks. This paper analyzes the NTP Protocol, uses the Timed Colored Petri Net(TCPN) to build the time synchronization process model of NTP. The simulation results verify the correctness of the model. Aiming at the delay attack on NTP, the relationship between the offset caused by the attack and the delay introduced is determined, the impact of delay attack on railway time synchronization network is analyzed, and the detection idea is presented. According to the relationship between the delay introduced by the attacker and the offset calculated by the client, the mitigation method of delay attack on NTP protocol is proposed. Then, the time synchronization process model of NTP is extended, the attack node and mitigation module are added to the original model to simulate the delay attack and its mitigation method. The simulation results show that the master-slave time offset after mitigation is less than 2 ms, and the proposed mitigation model can effectively mitigate the impact of delay attack on NTP.

关 键 词：铁路时间同步网 时间有色Petri网 网络时间协议 延迟攻击 时间同步 时间偏差 

分 类 号：U285.55[交通运输工程—交通信息工程及控制]