Seeking Verifiable Destruction of Nuclear Warheads
A longstanding conundrum surrounding efforts to negotiate reductions in nuclear arsenals is how to verify the physical destruction of nuclear warheads to the satisfaction of an opposing party without disclosing classified weapons design information. Now some potential new solutions to this challenge are emerging.
Based on tests that were conducted by the Atomic Energy Commission in the 1960s in a program known as Cloudgap, U.S. officials determined at that time that secure and verifiable weapon dismantlement through visual inspection, radiation detection or material assay was a difficult and possibly insurmountable problem.
“If the United States were to demonstrate the destruction of nuclear weapons in existing AEC facilities following the concept which was tested, many items of classified weapon design information would be revealed even at the lowest level of intrusion,” according to a 1969 report on Demonstrated Destruction of Nuclear Weapons.
But in a newly published paper, researchers said they had devised a method that should, in principle, resolve the conundrum.
“We present a mechanism in the form of an interactive proof system that can validate the structure and composition of an object, such as a nuclear warhead, to arbitrary precision without revealing either its structure or composition. We introduce a tomographic method that simultaneously resolves both the geometric and isotopic makeup of an object. We also introduce a method of protecting information using a provably secure cryptographic hash that does not rely on electronics or software. These techniques, when combined with a suitable protocol, constitute an interactive proof system that could reject hoax items and clear authentic warheads with excellent sensitivity in reasonably short measurement times,” the authors wrote.
See Physical cryptographic verification of nuclear warheads by R. Scott Kemp, et al,Proceedings of the National Academy of Sciences, published online July 18.
More simply put, it’s “the first unspoofable warhead verification system for disarmament treaties — and it keeps weapon secrets too!” tweeted Kemp.
See also reporting in Science Magazine, New Scientist, and Phys.org.
In another recent attempt to address the same problem, “we show the viability of a fundamentally new approach to nuclear warhead verification that incorporates a zero-knowledge protocol, which is designed in such a way that sensitive information is never measured and so does not need to be hidden. We interrogate submitted items with energetic neutrons, making, in effect, differential measurements of both neutron transmission and emission. Calculations for scenarios in which material is diverted from a test object show that a high degree of discrimination can be achieved while revealing zero information.”
See A zero-knowledge protocol for nuclear warhead verification by Alexander Glaser, et al, Nature, 26 June 2014.
But the technology of nuclear disarmament and the politics of it are two different things.
For its part, the U.S. Department of Defense appears to see little prospect for significant negotiated nuclear reductions. In fact, at least for planning purposes, the Pentagon foresees an increasingly nuclear-armed world in decades to come.
A new DoD study of the Joint Operational Environment in the year 2035 avers that:
“The foundation for U.S. survival in a world of nuclear states is the credible capability to hold other nuclear great powers at risk, which will be complicated by the emergence of more capable, survivable, and numerous competitor nuclear forces. Therefore, the future Joint Force must be prepared to conduct National Strategic Deterrence. This includes leveraging layered missile defenses to complicate adversary nuclear planning; fielding U.S. nuclear forces capable of threatening the leadership, military forces, and industrial and economic assets of potential adversaries; and demonstrating the readiness of these forces through exercises and other flexible deterrent operations.”
See The Joint Operating Environment (JOE) 2035: The Joint Force in a Contested and Disordered World, Joint Chiefs of Staff, 14 July 2016.
The United Kingdom is modernizing its stockpile of nuclear weapons and delivery systems, as detailed today in the Federation of American Scientists latest edition of its Nuclear Notebook, “United Kingdom Nuclear Forces, 2024”.
FAS believes the resolution is a necessary advancement of scientific understanding of the devastating consequences of a nuclear war.
The U.S. should continue its voluntary moratorium on explosive nuclear weapons tests and implement further checks on the president’s ability to call for a resumption of nuclear testing.
To help protect U.S. critical infrastructure workers, the next presidential administration should ensure ample supplies of high-quality respiratory personal protective equipment.