Harvey Newstrom wrote:
> This is the basis of the old DoD Tempest requirements that government
> secured vaults be lead-lined and have no external cables of any kind for
> power or data. A simple truck body does not meet the requirements for
> Tempest shielding.
>
> The ability to read computer screens and keystrokes via
> radiowaves has been
> around for decades. It is very easy to do, also. Keystrokes produce tiny
> radio bursts when the electrical connection is made. Each key is slightly
> different and has its own fingerprint. Capturing these and displaying
> keystrokes in order is easy. After that, simple code-breaking will
> determine which fingerprint matches which key. For example, in
> English, the
> letter "e" is most common. The most used key is the space bar,
> followed by
> the most used letter "e", etc. The longer you monitor, the more
> exactly the
> frequency table will converge with standard statistical tables.
>
> (Or so I've heard.....)
That matches my information on the subject. Of course, it isn't very
practical as a means of monitoring large groups of people. The monitoring
systems I know about can only watch one screen/keyboard pair at a time, and
have to be fairly close (within a hundred yards or so) to do it. This is
stale data, so I'm sure they've improved a bit in the meantime, but
monitoring large groups of people this way probably isn't practical yet.
Hopefully, by the time it can be done we will have interface technologies
that aren't so easy to monitor.
Billy Brown
bbrown@transcient.com
http://www.transcient.com
This archive was generated by hypermail 2b29 : Thu Jul 27 2000 - 14:10:36 MDT