Real-Time Rejection and Mitigation of Time Synchronization Attacks on the Global Positioning System

This paper introduces the time synchronization attack rejection and mitigation (TSARM) technique for time synchronization attacks over the global positioning system (GPS). The technique estimates the clock bias and drift of the GPS receiver along with the possible attack contrary to previous approaches. Having estimated the time instants of the attack, the clock bias and drift of the receiver are corrected. The proposed technique is computationally efficient and can be easily implemented in real time in a fashion complementary to standard algorithms for position, velocity, and time estimation in off-the-shelf receivers. The performance of this technique is evaluated on a set of collected data from a real GPS receiver. Our method renders excellent time recovery consistent with the application requirements. The numerical results demonstrate that the TSARM technique outperforms competing approaches in the literature.

I. Introduction

Infrastructures, such as road tolling systems, terrestrial digital video broadcasting, cell phone and air traffic control towers, real-time industrial control systems, and phasor measurement units (PMUs)  [1] heavily rely on synchronized precise timing for consistent and accurate network communications to maintain records and ensure their traceability. The global positioning system (GPS) provides a time reference of microsecond precision for these systems [2] –[5].