Year
2018
Abstract
Information Barriers are trusted measurement systems to confirm the authenticity of nuclear warheads based on their radiation signatures. Traditional inspection systems rely on complex electronics both for data acquisition and processing. Several research efforts have produced prototype systems, but it has proven difficult to demonstrate that hidden switches and side channels do not exist. After almost 30 years of research and development, no viable and widely accepted system has emerged.We pursue a fundamentally different approach: Our prototype of an inspection system uses vintage hardware built around a 6502 processor. The processor uses 8-micron technology (about 600 times larger than current 14-nanometer technology) and has only about 3500 transistors. Vintage hardware may have a number of important advantages for applications where two parties need to simultaneously establish trust in the hardware used. CPUs designed in the distant past, at a time when their use for sensitive measurements was never envisioned, drastically reduce concerns that the other party implemented backdoors or hidden switches on the hardware level. However, using vintage hardware also comes at a price, as the performance of the inspection system is limited, and data acquisition and processing has to be designed and highly optimized accordingly.In this talk, we demonstrate the performance of a prototype system using an Apple IIe and a custom-made open-source data-processing board connected to a NaI radiation detector for low-resolution gamma spectroscopy. Data processing and analysis is exclusively done on the Apple IIe hardware. In inspection mode, the Apple IIe is used as an information barrier, and the result of the analysis is simply displayed by a green/red (pass/fail) LED on the data-processing board. In demonstration mode, the information barrier visualizes the acquired low-resolution spectrum and the numerical result of a chi-squared test.