Side channel attacks: a novel approach using light variations

[1freedude]

Check out this new way of gaining keys to stuff that's not yours.

Hackers can steal cryptographic keys by video-recording power LEDs 60 feet away

Key-leaking side channels are a fact of life. Now they can be done by video-recording power LEDs.

arstechnica.com

First time I ever heard about this type of snooping was in "Cryptonomicon," by Stephenson. I think it was called Van Eck phreaking. Not sure how much Neal invented to make the story work, but it is based on real science. He is among my favorite authors.

 

[LabRat 891]

After giving the article a cursory glance...
I feel much more confident in my opinions that modern computers are under-shielded and many power circuits under-filtered.

1. A properly shielded enclosure and would mitigate a lot of the EM surveillance aspects. (Cheap cables purchased by EMF-ignorant IT departments, certainly do not help, either.)

2. Pure DC from a filtered (and induction shielded) supply would resolve the Power LED 'vector'. (Heck, I wonder if something as simple as a single STP pair for the LED's lead would mitigate the problem?)

 

[1freedude]

You're over thinking it.....a piece of tape over the led

 

[AnotherReader]

The article's last two paragraphs go over countermeasures and as @1freedude suggested, a piece of tape does the trick.

For now, people who are unsure about the vulnerability of their devices should consider placing opaque tape on power LEDs

The researchers recommend several countermeasures that manufacturers can take to harden devices against video-based cryptanalysis. Chief among them is avoiding the use of indicative power LEDs by integrating a capacitor that functions as a "low pass filter." Another option is to integrate an operational amplifier between the power line and the power LED.

My initial reaction upon reading the article was.