In Part 1, Part 2, and Part 3 of this series, the viability, technology, and capabilities of Improvised Electromagnetic Pulse Devices (IEMPDs) was described, and the threat of such weapons in the hands of non-state actors (terrorist groups, criminal gangs, etc.) discussed. But what can be done to detect and defend against the IEMPD threat? Now that we have laid out the threat of non-state actors using IEMPDs, it is important to look at the possible effects of these weapons in order to understand what countermeasures governments and organizations can take to decrease the risk stemming from IEMPDs.

Electronic details on integrated circuits (ICs) are becoming smaller to support much lower power loads. This makes today’s electronics more vulnerable to High-Power Microwave (HPM) and Transient Electromagnetic Device (TED) attacks than earlier ICs from the 1970s and 1980s. This is worrisome, since more and more of our modern infrastructure (electrical grids, water and phone systems, the Internet, etc.) relies on electronic systems that use integrated circuits and microprocessors (also called microchips). This trend toward greater automation and instrumentation means critical infrastructure systems are becoming increasingly vulnerable to HPM/TED attacks.

The damage caused by EMP attacks is unique in its effects, so it is important to differentiate between what is known as a “hard kill” and “soft kill.” A “soft kill” occurs when an EMP weapon creates a temporary disruption of the targeted system, causing its operational functions to be temporarily suspended. A “hard kill,” on the other hand, is when the EMP weapon causes permanent component damage rendering the targeted system functionally destroyed. Either kind of “kill” can serve the goals and interests of non-state actors, and those charged with defending facilities against EMP attack have to take into account both types of damage.

Defending against microwaves and radio frequency interference is not particularly difficult or expensive, and there are several methods to defend and/or harden against EMP or Electromagnetic Interference (EMI) attacks. The first step in hardening a site that might be vulnerable to EMP attacks, is to change network cabling from copper to optical fiber. This is effective, since when an EMP/EMI induced “spike” of high voltage or radio frequency (RF) energy hits the network, the copper wires channel the extra-generated power to the devices connected to the network. This means that potentially, a large number of devices can be harmed even in a small-scale EMP attack. Copper cables still dominate the market, since they are cheaper than fiber optic. However, fiber optic cables are increasingly used in data centers, and their immunity from electromagnetic attack would make such centers more secure in the event of an EMP attack. Another defensive measure is to secure the power supply to the site by using a motor-generator power isolator to produce “clean main power for internal distribution within the site.” However the motor-generator option might not work as a protection if a HPM or TED is set off inside the building.

Another measure to protect against EMI is to use a “Faraday Cage,” which is a metal enclosure that shields equipment from outside interference and is often used to provide protection from the effects of a lightning strike. It is possible to shield rooms, closets, and even entire buildings by insulating walls, floors and ceilings with metal shields, thus creating large Faraday Cages. However, no matter the size of the Faraday cage, it is important that the cables going in and out of it are fiber optic cables, because if they are made of copper the cage might be entirely useless; the copper wires would just channel the extra frequencies inside the cage. Also, all RF signals are blocked inside a Faraday cage, including cell phone signals. However, these kinds of structural measures require advance planning and some fiscal investment. Perhaps the easiest way to protect computers is to use military spec chassis that are built to survive battlefield conditions and events. The chassis of these systems would only have to withstand RF interference to protect against EMP, though there would be a need to modify all inputs to the computer because those could channel RF into the computer.

Another method that can be used to protect vulnerable data from being lost in case of an attack is the Portable Data Center (PDC). The idea behind PDC is that having backup data centers far away from the vulnerable sites adds another layer of protection. If the computer systems and data systems on the original site under attack itself are ruined, it is important that the backup data storage systems not be in the same building.

Under the principle of “it’s better to be safe than sorry,” governments and the private sector should and can adopt some of the measures described. These measures not only defend against possible attacks, but also against natural EMI phenomena. Many analysts believe that electronic warfare is going to be the way that wars are fought in the future, so with that in mind and the possibility of non-state actors using EMP, it is time to take proactive action, because the threat could be more imminent than we believe.