Secure and resilient localisation in cyber-physical systems
Time: Tue 2026-01-13 09.00
Location: F3 (Flodis), Lindstedtsvägen 26 & 28, Stockholm
Language: English
Subject area: Electrical Engineering
Doctoral student: Wenjie Liu , Programvaruteknik och datorsystem, SCS
Opponent: Associate Professor Aanjhan Ranganathan, Northeastern University, Boston, MA, USA
Supervisor: Professor Panos Papadimitratos, Programvaruteknik och datorsystem, SCS; Professor Ragnar Thobaben, Teknisk informationsvetenskap
QC 20251212
Abstract
Global navigation satellite system (GNSS) and other assisted positioning infrastructures provide ubiquitous, precise locations for cyber-physical system (CPS), from autonomous vehicles to location-based service (LBS) applications on mobile phones in daily lives. Combining multiple satellite constellations, network infrastructures, and onboard sensors typically makes the position solutions more accurate and robust than any single source alone.
However, civilian GNSS signals, Wi-Fi beacons, and cellular pilot signals lack cryptographic protection and are therefore vulnerable to signal spoofing attacks. Even if they can be upgraded to support authentication, meaconing or wormhole attacks can relay and falsify the wireless signals and then manipulate the localisation. More seriously, an attacker can selectively jam the wireless signals from specific infrastructures to force CPS to downgrade to less secure signals, which are later spoofed; coordinated adversaries can also target multiple infrastructures simultaneously to manipulate the positioning result.
This thesis is in the broad area of data trustworthiness for CPS, focusing on the security and resilience of localisation. Emphasis is given on securing the localisation based on GNSS, as they are relevant to a multiplicity of modern systems (e.g., connected vehicles, smartphones, and other Internet-of-Things (IoT) platforms). Significant efforts are dedicated to detecting attacks on position and providing secure and reliable location information, even in the presence of adversaries and benign faults (e.g., challenging propagation environments). Where perfect recovery is unlikely, the proposed methods aim for a best-effort position estimation by opportunistically fusing the remaining available benign signals.
These efforts are concerned with designing, analysing, implementing, and evaluating diverse protocols that address GNSS-specific attacks, other positioning signal attacks, and simultaneous GNSS with other signal attacks. The approaches are theoretically rigorous, are evaluated through detailed simulations, real-world experiments, and system implementation, proposing concrete defense mechanisms.