[Cryptography] Imitation Game: Can Enigma/Tunney be Fixed?

John Denker jsd at av8n.com
Sat Jan 10 03:57:46 EST 2015

On 01/09/2015 02:56 PM, ianG wrote:

> I was told yesterday that during WWII the Germans had some success
> parking submarines over undersea cables from UK to US, and using
> acoustics to pick up traffic!?  Anyone got any references to that?

That sounds like fiction to me.
Cables don't have any appreciable acoustic signature.

On 01/09/2015 10:02 PM, Ray Dillinger wrote:

>>I have heard the same story, regarding U-boats listening to
>> telegraph traffic by hearing the relays clicking at underwater
>> repeater boxes. It's not too unlikely, because the sonar guys
>> were also the radio guys, and knew Morse Code.  I got no
>> references though.

Repeater boxes with relays?  More fiction.

Undersea telegraph cables didn't use repeaters of any 
kind.  Some used lumped loading coils, but mostly they
used continuous loading.  No acoustical signal either

Undersea telephone cables require repeaters.  The first
such cables were laid in the 1950s.
  a) They didn't use relays, obviously.
  b) They weren't bothered by Nazi U-boats, obviously.

A list of cables, comprehensive or nearly so:

It shows no undersea repeaters of any kind before 1950.

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