False data injection attack detection for nuclear reactor based on chaotic time/frequency-hopping spread spectrum

False data injection (FDI) attacks represent a serious threat to securing nuclear reactor operation. Efficient FDI attack detection is essential to prevent related unforeseen nuclear accidents. However, owing to their design principles, the existing detection methods are limited in their ability to detect multiple types of FDI attacks. To address this issue, we propose a detection scheme for FDI attacks on a nuclear reactor based on the chaotic time/frequency-hopping (TH/FH) spread spectrum. The proposed scheme uses frequency hopping modulation, demodulation, and filtering of the signal based on hyper-chaotic sequences to limit the attacker's access to the system's real data and eliminate the adverse effects of attacks on the system. Furthermore, theoretical analysis derives the stability constraint of the frequency hopping frequency and demonstrates the detectability and defendability of the proposed scheme. Experimental simulations demonstrated that our proposed scheme can detect two typical FDI attacks, replay attacks and covert attacks, without compromising system operation, and defend against and reproduce covert attack signals.