Evidently, during WW2 (if not before) the UK & the US used Short Burst
Transmission for their top secret communications.

And, as I understand it, the following method was used:
 
a) Encryption of the message using a one-time pad (which provided
excellent protection).

b) The short burst transmission was used primarily to reduce the
possibility of detection and triangulation by the (for their day,
quite efficient) German listening posts. The Morse Code was recorded,
using a wire recorder, then speeded up by replaying the recorder at
multiple speed, then the code was transmitted as a burst at a
specified time and on a specified frequency.
The fundamental principle is to have the transmitter on for such a
short period of time that the detector units weren't able to
triangulate.
 
I imagine that this method required the use of a modulated carrier,
rather than continuous wave, less efficient unfortunately.

OK, so good so far. Or is it? Is my understanding correct?

But, critically, when did the UK & the US INTRODUCE this?

Many thanks

Bryan

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Request for Question Clarification by omnivorous-ga on 21 Feb 2004 08:12 PST

Bryan --

Good question.  The burst-mode or short-burst technique doesn't seem
to have been widely used, as there are many stories of Japanese and
German use of direction-finding (DF) equipment.  So far I haven't been
able to pin this one down, so will leave it to other researchers. 
(Among the sources that I've checked include Simon Singh's "The Code
Book.")

However, I can't leave this question without mentioning that you don't
get too far in the research here before running into the incredible
story of the Hedy Lamarr-George Antheil patent.  It was filed before
the U.S. entered the war (June 10, 1941) and eventually became a
seminal patent for spread-spectrum technology:
http://www.ncafe.com/chris/pat2/index.html

(Any Google search strategy using "spread spectrum" or FHSS will turn
up multiple Lamarr-Antheil references.)

Forbes Magazine says that the spread spectrum idea wasn't implemented
during the war but it's obviously closely-tied to ideas of short-burst
transmission.  And despite its reputation I wouldn't accept Forbes as
an authority on frequency-hopping here either, as this Salon.com
article supports the idea published elsewhere that the Lamarr-Antheil
ideas were used to secure communications for torpedoes:
http://www.salon.com/tech/feature/2003/03/12/spectrum/print.html

In addition, though many note that the Navy was skeptical of Lamarr's
ideas, she had an ex-husband in Germany who was a torpedo expert; and
her patent was promoted by Charles Kettering, the former leader of
General Motors' research who was instrumental in bringing technology
to the American war effort.

Best regards,

Omnivorous-GA

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Clarification of Question by probonopublico-ga on 21 Feb 2004 10:31 PST

Fascinating, Omnivorous.

Many thanks for having taken a good look and for turning up some interesting stuff.

More particularly, I appreciate your having taken the trouble to
provide this report. (I hate it when a question is locked for hours
and then nothing!)

I'll leave the Question open for a while, to see if anyone else can
take it further.

Warmest regards

Bryan

---

Clarification of Question by probonopublico-ga on 27 Feb 2004 10:22 PST

Hi, All

I think that this one has run out of steam ...

So My Grateful Thanks & Goodbye

Bryan

The German navy used a version of "Burst" to minimise there being
detected by the British High freqency Direction Finders, Huff-Duff.
However the Bletchly Park made this pointless.
Regd..Kemlo

Hi, Kemlo

As I understand it, Huff-Duff was useful anyway for pinpointing the
source of shortwave signals ...

For example, the Black Propaganda stations (like NBBS) which purported
to be being broadcast by dissidents in this country.

Great Comment.

Many thanks

Bryan

Well, not quite sure if this is what you are looking for (year of
first usage not mentioned).

Pictures of the U.S.ARMY M-108 POCKET-SIZED BURST CODE KEYER (go to number 190):

http://www.chss.montclair.edu/~pererat/mcpu.htm
or
http://w1tp.com/mcpu.htm

Regards,
Freddy

P.S. Website concerning Hedy Lamarr:
http://www.hedylamarr.at/

Hi, Freddy

Many thanks for the great links ...

Never realised (until Omni put me wise) what Hedy got up to.

An amazing woman.

Bryan

KURIER
A high speed "Burst" radio transmitter used by U-boats for
communications with home bases. The Kurier apparatus comprises a
number of dials upon which could be set such basic data as Lat. Long.
Time and fuel data plus numbers for pre-arranged phrases.
Upon transmission all this pre-set data would be sent at very high
speed in the form of a burst of pulses.
The Royal Navy had on its various bases surrounding the North Atlantic
Huff-Duff stations all linked by radio-teletype to the anti U-boat
headquarters in Liverpool.


Regards Kemlo

Great stuff, Kemlo, Many thanks!

Any idea of when this started?

Warmest regards

Bryan

Hi, Bryan

These pages seem to be rather interesting (but you may already know them):

"Spy vs. Spy" -- The Intelligence War in the European Theater:
http://www.ibiblio.org/hyperwar/ETO/Ultra/index.html

Battle of the Atlantic: Allied Communication Intelligence December 1942 - May 1945:
http://www.ibiblio.org/hyperwar/ETO/Ultra/SRH-009/index.html

ULTRA in the Atlantic: U-Boat Operations:
http://www.ibiblio.org/hyperwar/ETO/Ultra/SRH-008/index.html

ULTRA AND THE CAMPAIGN AGAINST THE U-BOATS IN WORLD WAR II:
http://www.ibiblio.org/hyperwar/ETO/Ultra/SRH-142/index.html

Counter Intelligence Corps History in World War II, Textbook, 1946:
http://carlisle-www.army.mil/cgi-bin/usamhi/DL/showdoc.pl?docnum=335

About the HyperWar Project:
http://www.ibiblio.org/hyperwar/about.html

Regards,
Freddy

P.S.
Found this website when searching for "Kurier" as mentioned by Kemlo.

Previous links to this website by GA Researchers:
http://answers.google.com/answers/search?q=hyperwar&qtype=all

Hi, Freddy

Many thanks for providing more links.

Knowing you, I'm sure that they'll be relevant & interesting.

But, I haven't yet had time to explore them.

That I will do later.

Warmest regards

Bryan

Wow, Freddy ... Just had a quick look before dinner (Roast Duck will
be ready in 10 minutes) but By Jove! You've done it again!

I shall now enjoy my duck all the more.

Many thanks

Bryan