Cyber Security of Urban Guided Transport Management according to MILS Principles

The Urban guided transport management system (UGTMS) as subway, transports from several hundreds of thousands to millions of passengers per day. Size and irreplaceability of subway transport capacity include the subway transport to the critical infrastructures of cities, regions or countries. Modern transport critical infrastructures contain in addition to physical and social parts also the cyber control systems and they are marked as cyber-physical systems (CPS). The CPSs are characterized by safety-critical nature, complexity, connectivity, and open technology. The CPS complexity, openness and dynamics form a large attack surface that may lead to failures and irreparable damage.
Multiple Independent Levels of Security (MILS) can meet the high system security requirements. The MILS is a high-assurance security architecture based on the concepts of separation and controlled information flow. The article discusses the possibilities of using the MILS platform in the data communication subsystem, which connects the individual UGTMS subsystems (Wayside subsystem, On-board subsystem and operation control subsystem). Therefore, the communication system should guarantee transmission parameters and do not affect security level of the respective subsystems.