alt Hacker NewsDoes any information leak along the power line? I remember having some device back in the day that let me create a LAN through my apartment's electric wiring.
I'm wondering if anything ends up back there thru the PSU during normal use of a computer, or if the high frequency components get filtered out.
(Though maybe secure computers do things differently with the power as well?)
Replies
Yeah, I've often wondered about this, but more locally (say within a local office, or maybe a data centre)...
I wonder if even "just" throttling up/down the CPU / GPU on tasks as morse code might be visible externally to other devices on the same mains supply. Obviously it would be very inefficient speed-wise, but a higher current (say + 300 watts for the GPU being used) should result in a slightly lower voltage on the mains supply I think for the duration?
Obviously things like PSUs could (I'm not an expert at any of this) get in the way of this, and I'd assume in data centres there's some isolation between different racks.
But for a scenario of DIY "airgapping" two machines in an office for AI testing (i.e. not doing it very well), it might be a plausible way of AIs finding to communicate if there's no actual network connection.
Obviously other electronic devices connected to the same mains circuit could also be adding their own noise, which might make it a lot harder to actually identify and decode the response, but... if ML/AI agents are good at anything, it's finding patterns, so I wouldn't want to bet against it being theoretically possible...
There is information that leaks through the power line as well, and the author of this paper also has a paper on how to exfiltrate through the power line at a much slower rate https://arxiv.org/abs/1804.04014
I heard that couple decades ago there was a product for "socket internet" - you plugged it into normal wall socket, and it communicated through power wires
Powerline Networking is what you are referring too.
Still available today, and has worked well for me when I've needed it.
A rogue PSU could modulate information back over the electrical wire. However getting it out will require doing a physical wiretap on potentially high-voltage electricals. Also, it will likely have to be exfil'd at or across a power transformer sitting outside the data centre. Not sure if the signal will survive long enough (like literally, in line length terms), for exfil to work.
brb reviewing some EE material...
But don't expect much from me... I wanted to do a final year project in Power Line Communication for my electrical engineering undergrad. Then-me decided it was a dead end... cannot go WAN-scale; too much line noise and signal transmission power loss. I did something else with power electronics---I can't remember---but then again, my undergrad was also a dead end :p