24 Apr
2020
24 Apr
'20
2:06 a.m.
On Apr 23, 2020, at 8:01 PM, William Pechter
<pechter at gmail.com> wrote:
Actually the fun mil-spec VT100 was the Tempest VT100. Metal case to avoid radiating
information into the air and a metal cased VT100 keyboard.
Dropped that in my lap only ONCE at the FBI facility I was Field Service for. Ugh.
bill
One of the strangest crypto / security papers I ever read was from famous cryptologists in
England, who designed a font that dramatically cuts emissions from a video monitor. You
could pretty much get TEMPEST compliance simply by downloading that font and using it for
your text instead of the stock font. The magic, as I recall, was soft edges, so the
square waveforms typical of a text video signal were smoothed.
paul