See also: <a href="https://en.wikipedia.org/wiki/Cryptonomicon" rel="nofollow">https://en.wikipedia.org/wiki/Cryptonomicon</a><p>...and the entertaining tangent story involving Van Eck Phreaking and vintage furniture.
Markus Kuhn’s work on “optical eavesdropping” — reconstructing a CRT image from reflected visible light — is really interesting: <a href="https://www.cl.cam.ac.uk/~mgk25/ieee02-optical.pdf" rel="nofollow">https://www.cl.cam.ac.uk/~mgk25/ieee02-optical.pdf</a>
This SDR implementation looked really interesting for sniffing monitor output - <a href="https://github.com/martinmarinov/TempestSDR" rel="nofollow">https://github.com/martinmarinov/TempestSDR</a><p>Alas I don't have a suitable SDR to try it with.
If you want to play around with Van Eck Phreaking, try <a href="https://packages.debian.org/sid/tempest-for-eliza" rel="nofollow">https://packages.debian.org/sid/tempest-for-eliza</a> , which lets you listen to MIDI-like music via AM radio from your computer monitor.
Unrelated, but at the bottom of <a href="http://celeriac.net/sx/public/" rel="nofollow">http://celeriac.net/sx/public/</a> is a sonification of Van Eck's sequence