[GreenKeys] Declassified NSA Document Reveals the Secret History ofTEMPEST

[Duncan M. Brown]

Read the declassified NSA document at 
http://www.nsa.gov/public/pdf/tempest.pdf  (unfortunately only about half
of it was declassified)

In the Army, all of our Kleinschmidt machines had been modified to run a 50
microamp (not milliamp) loop between the keyboard/TD contacts and the
crypto equipment (KW-7s & KW -26s) to cut down on clear-text eminations
from the transmitting contacts.  They also played music outside the secure
areas to try to prevent easedropping.  (It was said that the sounds of the
TD fingers poking through the tape and  keys hitting a platten could be
used to reconstruct a message; though that sounds like quite a stretch)

If you are in the Washington/Baltimore area, be sure to visit the NSA
museum (it is hidden in behind a Shell station): 
http://www.nsa.gov/museum/index.cfm

have fun,

Duncan Brown, K2OEQ
Army Security Agency, 1966-1970