AES-256 keys sniffed in seconds using E200 of kit a few inches away
https://www.theregister.co.uk/2017/06/23/aes_256_cracked_50_seconds_200_kit/
Sideband attacks that monitor a computer's electromagnetic
output to snaffle passwords are nothing new. They usually
require direct access to the target system and a lot of
expensive machinery - but no longer. Researchers at Fox-IT
have managed to wirelessly extract secret AES-256 encryption
keys from a distance of one metre (3.3 feet) - using EUR200
(~US$224) worth of parts obtained from a standard electronics
store - just by measuring electromagnetic radiation. At that
distance sniffing the keys over the air took five minutes, but
if an attacker got within 30 centimetres (11.8 inches) of a
device, the extraction time is cut down to just 50 seconds.
