[81335] in Cypherpunks
FW: TV Commercial
daemon@ATHENA.MIT.EDU (Roger J Jones)
Fri Jun 6 17:17:03 1997
From: Roger J Jones <cyber@ibpinc.com>
To: "'cypherpunks@cyberpass.net'" <cypherpunks@cyberpass.net>
Date: Fri, 6 Jun 1997 15:46:30 -0500
Reply-To: Roger J Jones <cyber@ibpinc.com>
Having spent a fair amount of time on the high seas on gray ships I =
found the following interesting in that:
1) Back in WWII days Aldis lamps were a pretty good option. Unless you =
had a submerged enemy sub in your convoy you would most likely notice =
anyone who could intercept your communications. Since of course convoys =
could travel faster than submerged subs the exposure was also limited in =
time. Add of course the fact that most of the messages were in code, =
frequently unique for a given transit.
2) Consider the changes in today's environment:
a) Image intensifying lenses make over the horizon (cloud bounce) =
reception possible.
b) Subs can move faster underwater than most surface ships.
c) Satellites could pick up the light pulses - either directly (if low =
horizon) or reflectively (off the water)
d) I suppose that the right spectrum could also pick up the heat caused =
by the filament of the lamp.
Of course, since it now takes about 45 gizillion people on a ship to =
"sign out" a message for release, the only messages that go out over =
Aldis lamps are the signalmen swapping scuttlebutt and sea stories in =
the name of "on the job training"
"Fair winds and following seas!"
An old salt.
-----Original Message-----
From: Bill Frantz [SMTP:frantz@netcom.com]
Sent: Friday, June 06, 1997 11:13 AM
Subject: Re: TV Commercial
At 12:34 AM -0700 6/6/97, David Lucas wrote:
>It's a nice thought, but the image is all wrong. Two ships =
communicating
>via Aldis lamps (presumably, I haven't seen the ad) using Morse at a =
guess,
>isn't what I would call very secure communication.
Well, the Japanese managed to keep secure communications when sneeking =
up
on Pearl Harbor, and I assume they used something similar for =
ship-to-ship
communications. Narrow beam, and everyone who can receive is in sight =
is
nice.
