Buddy Tag

Previous arms control agreements have focused on strategic weapons stockpile reductions because verification procedures were more easily codified and agreed upon by both parties. In order to achieve deep cuts in nuclear stockpiles, however, the challenge of counting warheads and verifying numerical limits on stockpiles must be addressed. Any proposal would intersect many aspects of the warhead lifecycle: deployment, maintenance, storage, and disposition. Since these activities are considered to be top secret, technical support for arms control agreements has focused on protecting and authenticating classified data collected in the treaty verification process. Given the challenges to these methods, it is advantageous to design approaches and procedures which do not collect such data in the first place. Non-intrusive technologies and procedures hold promise as they are more likely to support proposals which will be actually acceptable and implementable to the hosts. Buddy tag is one such approach, seeking to address the challenges of warhead counting in a deep-cut scenario.

Conventional approaches to tagging generally involve the direct application of an active or passive tag to each warhead or treaty-accountable item (TAI) at the time of declaration by its owner. These declarations are then verified through inspections, where the tag is examined to ensure it is genuine. In order for such an approach to be successful, however, the tag must be attached to the item in such a way that “lifting” the tag off the item would irreparably destroy the tag. Additionally, the tag must be affixed to a critical component of the item, one which is not detached or replaced easily. Rather than this direct tagging approach, we propose a companion tag which would act as a token, proving ownership of the TAI without needing to present the item itself for close inspection. The buddy tag concept combines a simple yet robust technology with an inspection procedure which together allow numerical limits on TAI to be verified.

Buddy Tag supports the verification of numerical limits on TAI while remaining sensitive to the security concerns of weapons states. Originally conceived by researchers at Sandia National Labs, Buddy Tag acts as a token, proving ownership of a treaty-accountable item (TAI) and transforming a numerical limit into a ban on untagged items. This approach is unique because the Buddy Tag is not physically attached to the item with which it is “tagged”—rather the tag follows the item around Each treaty signatory receives one Buddy Tag per TAI and agrees to ensure that each TAI has a companion Buddy Tag on-site at all times. This pairing is verified using short-notice inspections which confirm that the number of tags exactly equals the number of TAI on-site. To ensure confidence in the findings of inspectors, Buddy Tag is equipped by an on-board sensor platform which indicates whether the tag has been moved within the short-notice inspection time period.

Together with the Princeton Lab for Electrochemical Energy Systems Research and partners at Sandia National Laboratories, we are building a prototype buddy tag as a demonstration of the concept. Our prototype combines a MEMS-based inertial measurement unit (IMU) with a unique tamper-indicating enclosure, and uses a two-mode motion detection algorithm to distinguish covert movement attempts from vibrations in the surrounding environment.

More to explore:

  • S. Jordan, Buddy Tag’s Motion Sensing and Analysis Subsystem. Sandia National Laboratories, Albuquerque, NM, 1991.
  • S. DeLand, A. Glaser, J. Brotz, A. Kim, D. Steingart, and B. Reimold, A Fresh Look at the Buddy-Tag Concept. 57th INMM Annual Meeting. July 24-28, 2016, Atlanta, Georgia, USA.
  • Minimally Intrusive Verification of Deep Nuclear Warhead Reductions: A Fresh Look at the Buddy Tag Concept, 57th Annual INMM Meeting, July 24-28, 2016, Atlanta, Georgia.