The current train systems are heavily computerized which makes them highly prone to cyberattacks. Many functions in the trains are controlled by programmable logic controllers (PLCs) which make them an attractive target of attacks. By compromising the train’s PLCs, attackers can cause trains to operate in an unsafe environment and even lead to a fatal accident. In this paper, we investigated the current PLC redundancy framework in train systems which only resolves the issue of availability of the PLC while overlooking the integrity of the data being synchronized between PLCs. We proposed a new PLC redundancy framework encompassing of isolation and recovery mechanisms which are able to provide both availability and integrity. We developed a proof of concept and demonstrated its viability on our laboratory training skid.

当前的火车系统是高度计算机化的，这使其非常容易受到网络攻击。火车上的许多功能都由可编程逻辑控制器（PLC）控制，这使它们成为攻击的诱人目标。通过破坏列车的PLC，攻击者可能导致列车在不安全的环境中运行，甚至导致致命事故。在本文中，我们研究了列车系统中当前的PLC冗余框架，该框架仅解决了PLC的可用性问题，却忽略了PLC之间同步数据的完整性。我们提出了一个新的PLC冗余框架，其中包含隔离机制和恢复机制，这些机制能够同时提供可用性和完整性。我们开发了概念证明，并在我们的实验室训练橇上证明了其可行性。