Abstract: Attack defense trees are used to show the interaction between potential attacks on a system and the system defenses. In this talk, we first present how to use attack trees to generate security test cases to provide a systematic security evaluation. This is done by transforming attack trees into equivalent formal representations where generation of test cases can be done by model checking. Then, we present an extension of attack defense trees with sequential composition, allowing for the description of attacks that are performed as a sequence of steps. The main contributions of our work are a formal representation of attack defense trees with sequential conjunction, a demonstration that this representation is equivalent to a process-algebraic one, and an algorithm for identifying the existence of attacks.

Bio: Dr Hoang Nga Nguyen is a Research Fellow in Cybersecurity and Cyber-Physical Systems. His research is in the area of Formal Methods. His work focuses on modelling and verifying qualitative, quantitative and secure/safe properties. In the last two years, he has been in several research projects. In particular, ACID aimed at developing methods detecting collusion of Android applications. These methods are based on machine learning and model checking. Another example is Ditto, investigating how to model railway systems for measuring capacity. His active research agenda also includes cybersecurity in automotive and autonomous systems.
Before, Dr Nguyen worked at the University of Nottingham and Swansea University. During this time, he involved in a couple of EPSRC-funded projects. Both involved developing methods, abstraction techniques and formal tool support. The first, VRBMAS, is for verifying resource-bounded autonomous systems. The second, SafeCap, is for large-scale railway systems.

Currently, he is an associate member of the Verification & Validation of Autonomous Systems network. He is also a member of European Technical Working Group on Formal Methods in Railway Control.

He has been on the PC of several international conferences and workshops. He also provides reviews for several journals. Dr Nguyen has over 40 publications.