Developing a Framework to Address Performance and Security Protocol Concerns in Identity Management for Interoperable Positive Train Control Systems

The timely delivery, correctness, integrity, and authenticity of signaling messages sent to trains running under Positive Train Control (PTC) are necessary to ensure safe train operations and to prevent the insertion of malicious messages or the alteration of authentic ones in transit in train control traffic. Mutual authentication of trains and messages must occur when a train enters a zone under PTC from dark territory, when a train moves from one railroad company’s network to another’s, when a train communicates with a Wayside Interface Unit, or when it communicates with the head of a work crew on the railroad line. We describe concerns about performance requirements and protocol security related to this process, and develop a framework for defining use cases, performance models, and secure methods to meet them.