QUASAR Fuses a CNN Spectrogram Encoder With a Variational Quantum Circuit and Matches Classical SAR Authentication on 10% of the Training Data

arXiv 2608.20240·low signalXBlueskyLinkedInCopy link

X-band SAR satellites (8-12 GHz) lack physical-layer authentication, and classical RF fingerprinting underfits the IQ phase nonlinearities that distinguish satellite hardware. QUASAR is presented as the first quantum-classical hybrid for this task, and its headline claim is data efficiency: it matches classical baseline accuracy using only 10% of the training data, with data collection being the most expensive part of building such a system. Under replay, crafted-IQ injection, and space-borne spoofing it rejects spoofed transmissions 89.7%, 94.1%, and 81.3% of the time respectively.