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.