Zero-Knowlege Protocol for Nuclear Verification of Arms Reduction Treaties*

It is well known that nuclear physics brought us the most dangerous weapons the world has ever known, but it less well known that nuclear technology is key to limiting this danger. 

A key conundrum of bilateral arms reduction treaties is that each side must be confident that the other side's weapons being dismantled are of the type agreed. However, at the same time neither side may learn about the design or composition of the other’s weapons. A new class of approaches to this problem is based on the concept of the Zero-Knowledge Protocol [1]. Under this protocol, the Inspector selects M warheads from the Host's actively deployed stock, while the Host selects N warheads from storage, all for dismantlement. In its essence, this reduces the problem to one of providing sufficient confidence that all M + N warheads are identical, without revealing sensitive information, by making physical, in general nuclear, measurements that are fundamentally differential. Even the noise in the measurements must not reveal information. This approach is being studied for radiographic imaging using 14.1 MeV neutrons, driving fission with sub-MeV neutrons for discrimination between fissile and fertile isotopes, warhead self-imaging using neutrons from spontaneous fission of Pu-240, measurements of nuclear resonance fluorescence, and measurements of absorption by epithermal neutron resonances.