I first heard of electromagnetic pulse or EMP attacks probably about twenty-five years ago. I had heard years ago of the possibility of EMP damage from an atmospheric nuclear explosion, but it was only fairly recently that I heard of EMP as a direct attack.
Television and the movies show police stopping vehicles with EMP, and in one of my favorite movies Ocean’s Eleven (2001), the team uses a device they call a “Pinch” to generate an electromagnetic pulse to shut off the electrical power to parts of Las Vegas, NM. The American Physical Society on aps.org reports that the influence for that Pinch was a device with a similar name developed at Sandia National Labs in Albuquerque, NM, a site not too far from where I’m writing this post. However, the Sandia Z-pinch as it is known didn’t (or doesn’t) produce the kind of EMP necessary to create a massive power shutdown. The Sadia folks did a lot of work on EMP including the Trestle project on which some friends worked.
The idea is real, however, and doesn’t need a device the size of the Z-pinch or even the Pinch from the movie. Instead, as an article on the IEEE Spectrum site explains, the device could be briefcase-sized to target, say, a single building. That article is only slightly technical and details the attacks well. The article is well-written and in no way “fear-mongering”. (If it matters, I am a Senior Member of the Institute of Electrical and Electronic Engineers, the IEEE.)
The basic physics is simple: a large brief pulse of electromagnetic (EM) radiation can induce large electrical currents in sensitive devices. The electronics we use have become much more sensitive to EMP as they have become more complex and the circuits have become smaller. The smaller circuits have smaller transistors and other devices and those are more sensitive to an influx of current. The idea that an attacker with a device in a brief case or a small vehicle could take out even a handful of computers, phones and other devices is a bit scary.
How can we avoid such attacks? One suggestion in the article is “…you could surround a building with a broad green meadow protected by fences, thus taking advantage of the falloff in an antenna’s electric field strength with distance.” You can see many instances of this defense in the Washington DC area. (Many of those “meadows” are likely to prevent electronic eavesdropping, however, but the idea is exactly the same – the signals decrease with distance.)
The main defenses you and I will see are also mentioned in the IEEE article: electromagnetic shielding for devices, rooms and buildings. We discuss these in Learning Tree Course 468, System and Network Security Introduction as an eavesdropping defense, but as I noted above, they can help defend against EMP attacks as well.
Let us know in the comments below about your EMP concerns.
To your safe computing,