March 26, 2023
Marshall L. Brown Jr.
Executive Summary
On December 13, 2022, CNS Technical experts provided a proof-of-concept demonstration of a new methodology for secure nuclear warhead data exchanges, which was funded by the Department of State’s Verification Fund. Such a methodology would support a verifiable nuclear warhead arms control treaty or other measures addressing nuclear warheads. The Warhead Tracking System methodology is based in part on the extensive technical engagements on nuclear warhead inventory management systems, under the Cooperative Threat Reduction (CTR) Nuclear Security program, from the mid to late 1990s up until the CTR agreement expired in 2013. The unique characteristics of each individual warhead are represented by a string of data, which for the purposes of this methodology is called a “passport.” These passports can be exchanged securely using cryptographic “hash codes” (commitments) and would be periodically updated to account for warhead movements and operations.
The technical team developed and presented notional US and Russian passports and showed how that data would be transformed into hash codes. Because neither side would be prepared to disclose all data on its nuclear warheads, this methodology includes a data challenge procedure that would require certain data to be divulged, which, if confirmed to be valid, would provide some assurance that other data represented by the hash codes are valid. The technical team also explained the use of a mathematical proof that could be used by the sides to determine whether the data in the hash codes was valid by checking if it followed a particular set of rules, without revealing the data itself. The next step in developing this methodology is to integrate it into a comprehensive verification protocol, which is the subject of a forthcoming V Fund project.
Attendees at this demonstration were from The White House, Departments of State, Energy and Defense, National Laboratories, National Academy of Sciences, and NGOs (total of 25). A number of questions were posed during the demonstration that the technical team will take into account in the continued development and evolution of this methodology
