Spectral Security Imaging System (SSIS): Optical Authenticity for Hyperspectral Pushbroom Imaging

Abstract

Ensuring authenticity of hyperspectral imagery (HSI) at the moment of acquisition is critical: subtle spectral attacks can mislead downstream analysis before digital defenses take effect. By injecting the optical key before digitization, the effect is created in hardware and cannot be replicated in software, resulting in stronger protection. We present the Spectral Security Imaging System (SSIS), an acquisition-stage approach that injects a data-aware {additive} spectral key in the optical path of a pushbroom imager, binding integrity to the measurement while preserving the class-informative structure. We describe the complete system forward model, detector–key joint optimization, and a laboratory prototype together with a thorough calibration process. A laboratory dataset (unsigned and optically signed cubes) supports two evaluations. For manipulation detection, SSIS achieves detection accuracy of {92%} with visual distortion of {PSNR = 41.5 dB} and {SSIM = 0.981}. For downstream classification on clean data, macro-F1 remains close to the unsigned ceiling, about 93% of the monochromator baseline (0.915 vs 0.981) and about 99% of the pushbroom baseline (0.892 vs 0.903), while outperforming multiplicative and watermarking baselines by up to 16.1 points in macro-F1 and 19.4 points in accuracy.