Communications security concerns in communications based train control

摘要

Since the late 1980s, Communication Based Train Control (CBTC) Systems for freight and passenger rail have been under development in the United States. These systems have been advertised as offering significant enhancements in safety by ensuring positive train separation, enforcing speed restrictions, and improving roadway worker protection. In order to maximize the effect of these safety enhancements, it is necessary for CBTC systems to address security issues common to wireless computer communication systems. This paper introduces the role that CBTC systems play in railroad methods of operations, as well as the vulnerabilities of communications systems being manifested in CBTC. It provides a classification of attacks against CBTC systems, and identifies the security controls to mitigate these attacks.rnThe level of risks associated with these security issues have increased from the first CBTC system introduction, primary because of increases in the means of exploiting the associated vulnerabilities. Exploitation that could compromise the system safety capabilities can take the form of any number of different types of attacks (e.g. jamming, etc). Failure of the CBTC system designer to adequately address these attacks could allow a malicious party to exploit CBTC vulnerabilities, effectively neutralizing the safety advantages of a CBTC system. Recent non-CBTC train-to-train collisions causing release of toxic inhalants and resulting deaths illustrate that a lack of CBTC system safety capabilities could have catastrophic results. Fortunately, these attacks can be mitigated using various security controls. Understanding the attacks and the respective mitigating security mechanisms is therefore key to effectively implementing CBTC safety advantages.