The machine is protected by a plastic case, so the current would have to be some type of wave. Think of device like a calculator, no installed wireless cards. Changing power supply is not possible due to setup, cables are secured etc. We need to find a way of this working for our presentation, so assume the perpetrator is moderately skilled.

I'm not entirely sure you're understanding me. Without something to receive the power (which wireless cards are designed to do), what you're wanting to do is to induce a current across the entire machine, and have it only temporarily disable the device. This would take an amount of knowledge about the device, and about the workings of EM devices, combined with a staggering amount of power (EMPs are typically said to use nuclear explosions to generate their "waves"), that the entire thing would be pretty much unfeasible. What you're wanting is technically possible, but massively difficult.

Okay. We are sure it is possible as we have seen a box attached to one of our devices' casings which caused it to not work until removed. Sadly we were unable to do any forensics on the device, it has been destroyed as they caught onto us,

Difficult to know without knowing more about the device (all you've said is that it is a device, and has a plastic casing). If there's a component that's particularly susceptible, you might be able to generate interference, but it's difficult to speculate without information.

Think of the device like an electric "smart" meter. That shape, cost, design, hardware, almost similar security.

@k1308517: Please update your question with this information and dont just comment! A "computer" can be anything: Supercomputer, server, desktop-pc, raspberry pi, smartmeter, tablet, ... all with different casings and different ways to protect them. Your question needs more information for us, else it is very hard to make an assumption about the possibility of an attack.

@k1308517 Are you absolutely sure the attacker actually crashed the processor in the computer instead of say jamming the communication lines or the reading mechanism?

@billc.cn 100% sure because it was an electrician (not a coder), and jamming lines would have no effect since when restored it would resume sending.

@k1308517 Except that that's what you're indicating happened. You're saying that someone "attacked" your device, and it stopped working for a period of time, then worked fine again. Which pretty much mirrors the idea that someone jammed the communication line, or turned the thing off.

The person performing the attack had no networking/programming skills, he was an electrician. Furthermore, turning the device off is not possible, for example if you disconnected a smart meter how on Earth would power reach your home? Whereas if you "jam" it electric will still pass through the meter but you will not be charged. I have repeatedly said compare it to a smart meter (or similar device) since I can't sadly explain about our product (although it is extremely similar to the above). Thank you.

@k1308517 Is the device connected to the terminals of the meter or simply attached to the case? Do you know the rough dimensions of the device? Is the device powered in anyway?

@billc.cn Attached to case. Not sure about how it is powered, however due to accessibility it most likely is battery powered.

Another possibility is radiation source, but I am not sure how you would verify or defend against it....

← 13 messages moved from Discussion on answer by Jozef Woods: Crash a computer using waves or similar techniques?

@k1308517 - please keep all discussion in here. Your comments on the various posts just lead to a sprawling mess of unfocused discussion.