This arXiv preprint (dated 2026, not yet peer-reviewed) outlines a proof-of-concept analog circuit that restricts Neutron Resonance Transmission Analysis (NRTA) to count rates within narrow eV resonance windows rather than full time-of-flight spectra. The approach uses only discrete, inspectable components to prevent extraction of geometric or isotopic details beyond a binary authenticity signal. While the source demonstrates circuit functionality in principle, it omits quantitative error rates from realistic neutron scattering backgrounds and does not address calibration drift over multi-week treaty inspection campaigns. Earlier peer-reviewed work (Kemp et al., Nuclear Instruments and Methods A, 2016) established NRTA's isotope-specific absorption lines but relied on digital processing that leaked excess information; the new analog encryption layer directly mitigates that flaw. A related 2022 study on information barriers (Danagoulian group, Science & Global Security) highlighted political acceptance barriers that this transparent hardware design could overcome. Limitations include dependence on a stable, transportable neutron source and the untested assumption that treaty parties will certify the analog chain without demanding digital logging. If adopted, the protocol could anchor future treaties requiring actual dismantlement rather than stockpile caps, turning physics itself into the cryptographic primitive that aligns verification with non-proliferation goals.