New technology could monitor nuclear weapons

An international research team has developed a way of monitoring changes in nuclear silos without revealing secret information about the stored weapons.

The technique, created by researchers from Bochum, Princeton and Harvard, could be used to verify whether countries are abiding by nuclear disarmament treaties.

It uses electromagnetic waves in the radio frequency range, which bounce off walls and objects and create a unique radio-wave map. If a warhead were removed or added to a storage facility, the pattern would change and this could be detected.

The idea is that country A could monitor the nuclear silos of country B by requesting regular radio maps of the room. But in order to stop countries simply sending old radio-wave maps over and over again, researchers had to add another layer, explained Dr Ulrich Ruhrmair from the Horst Gortz Institute for IT Security in Bochum, Germany.

This involves installing 20 rotating mirrors in the room, which can be remotely adjusted. These mirrors reflect radio waves, thereby changing the pattern of electromagnetic waves depending on their precise arrangement and positioning.

Country A would be able to change the pattern of mirrors each time it requested a radio map, rendering previously recorded maps useless. It would then verify them against maps recorded when the system was first installed.

The system is being tested in a container using dummy warheads and 20 mirrors, which allows for a vast number of different mirror arrangements.

“The challenge is to make sure that the monitored country doesn’t learn to predict the next mirror setting over time,” says researcher Dr Christof Paar. To prevent this, the researchers use an unpredictable cryptographic protocol to align the mirrors to make it impossible to predict what will come up next.

It’s hoped that such technology will help move the world towards nuclear disarmament by allowing countries to monitor changes in the nuclear silos of others.

Of course, such a system would rely on a degree of trust between nations when it comes to installing their equipment, and if a government was dead set on a secret weapons programme it could always store new warheads somewhere else.