城市轨道交通信号系统信息安全风险辨识

从城市轨道交通信息安全面临的严峻形势出发,介绍城轨交通信号系统组成,并对信号系统各子系统功能进行阐述。城轨交通信号系统是保证列车安全、准点、高密度运行的重要技术装备,主要由列车自动监控子系统、列车自动防护子系统、列车自动运行子系统、联锁子系统组成。根据信息安全风险分析模型,识别城轨交通信号系统信息安全的威胁来源及核心资产。由于城轨交通系统属于工业控制系统的典型系统,城轨信号系统则具备工控系统的一般性特点,继承工控系统的脆弱性。针对国内城轨交通信息安全研究的空白之处,结合工控系统不同层级结构的脆弱性,从技术和管理两个方面进行信号系统的信息安全风险辨识,通过分析发现存在物理安全、网络安全、主机安全和应用安全等层次上的风险。风险辨识结果反映出城轨交通信息安全存在大量的薄弱环节,以期为日后的研究和防护工作的开展打下基础。

Identification of Information Security Risk in Urban Rail Transit Signal Systems

Based on the critical situation of information security in urban rail transportation systems,a signal system is introduced for the latter,and the functions of each subsystem of the signal system are elaborated.The signal system comprises the core technology and equipment that ensure the safety,punctuality,and high-density operation of trains,and primarily consists of an automatic control system,automatic protection system,automatically operated subsystem,and interlocking subsystem.The risk sources and core assets of information security in the signal system are identified using an information security risk analysis model.As the urban rail transportation system is a typical industrial control system,its signal system is characterized by the general traits and vulnerabilities of the latter.Our studies in the field of transportation information security of domestic urban rail systems and the vulnerabilities at different levels of the industrial control system have been performed keeping the two aspects of information security risk identification,viz.,technology and management,in mind.We have identified the risks existing in the current level of physical,network,host,and application securities through proper analysis.Our results highlight the weaknesses of urban rail transportation information security,and pave the way for future research and protection work.