Universally composable multi-factor authentication scheme for rail control systems

Abstract

Rail transportation has emerged as a critical component of modern land transportation. With the development of informatization and intelligence, rail control systems have shifted from traditional closed environments to open networked environments. While interconnectivity offers operational benefits, it also exposes systems to severe security risks. As a safety-critical infrastructure, train operations rely on robust security mechanisms, among which user access authentication and train handover authentication are indispensable. However, despite the considerable research devoted to the latter, the former has been largely neglected. Moreover, although industry standards emphasize the deployment of multi-factor authentication (MFA) in industrial control systems or railway systems, no practical MFA scheme tailored for rail control systems has been developed. This gap stems from two challenges: (1) The inherent difficulty of designing protocols that can simultaneously withstand powerful adversaries and satisfy multiple security goals; (2) The deployment complexities arising from the heterogeneous, distributed, and large-scale nature of rail control systems, together with the large number of concurrently operating subsystems. To address these challenges, this paper analyzes two state-of-the-art MFA protocols and shows that neither ensures multi-factor security nor forward security. We then propose the first MFA scheme for rail control systems, built on a wireless sensor network architecture, and prove its security within the universal composability framework. A comparative evaluation with 68 representative MFA schemes reveals shows that our protocol achieves strong security. Furthermore, experiments performed on a laptop with an AMD Ryzen 7 5800H processor validate the high efficiency of the proposed scheme.