Analysing the Safety of Collision Avoidance Protocols in Aviation

自动和半自动车辆的防撞协议构成了安全可靠的全球交通系统的支柱。就航空而言，交通警报和防撞系统(TCAS)负责确保飞机的安全，减少空中相撞的机会。然而，TCAS的安全性和有效性尚未从安全角度进行分析--特别是考虑到与近20年前设想的一项协议有关的当前和不断增加的空中交通水平。本研究项目旨在模拟和分析TCAS所规定的安全运行所需的约束条件。目标是确定TCAS是否仍然满足其在避碰方面的操作目标，并进一步调查它是否容易受到恶意攻击。我们研究方法的创新之处在于，我们使用真实世界的数据(飞机转发器消息)来分析TCAS的安全性，而不是依赖于模拟或统计测试。这使我们能够收集有关TCAS在世界各地使用的准确和最新信息。根据我们的结果，我们将处于独特的地位，能够了解TCAS带来的潜在风险，以及它们带来的后果，最重要的是--可能的补救方法。该项目属于EPSRC“全球不确定性”研究领域，更具体地说，属于这一类别下的“网络安全”核心研究主题。

Collision avoidance protocols for autonomous and semi-autonomous vehicles form the backbone of a safe and reliable global transportation system. In the case of aviation, the Traffic Alert and Collision Avoidance System (TCAS) is responsible for ensuring the safety of aircraft and reducing the chances of mid-air collisions. However the safety and efficacy of TCAS is yet to be analysed from a security perspective-especially given the current and ever-increasing levels of air-traffic with regard to a protocol conceived nearly two decades ago.This research project aims to model and analyse the constraints specified by TCAS that are required for safe operation. The goal is to determine whether TCAS still meets its operational goals with regard to collision avoidance, and further investigate whether it is vulnerable to malicious attack. The novelty of our research methodology is that we use real-world data (aircraft transponder messages) for our analysis of TCAS's safety, rather than relying on simulations or statistical testing. This allows us to glean accurate and up-to-date information regarding the usage of TCAS around the world. Based on our results, we are then in a unique position to understand the potential risks posed by TCAS, the consequences posed by them, and most importantly - possible methods of remedying them. This project falls within the EPSRC "Global Uncertainties" research area, and more specifically within the "Cyber-Security" core research theme under this category.