Luftwaffe Personnel spying for Allies?

[Nick Beale]

Originally Posted by RT

further concerning Ultra, was the code "cracked", or "sold", or "found"/ case of the submarine/???

remi

The answer is not simple! Two very good books on this are "Seizing the Enigma" by David Kahn and "Enigma: the battle for the code" by Hugh Sebag-Montefiore.

The Allies broke into the day's Enigma settings by a variety of methods (including statistical analysis and computers) but even when you have done that, the message may still be in another code. The German Navy used a system of two-letter combinations ("bigrams") to denote weather, wind speed/direction etc. A lot of effort went into capturing the relevant code books.

[John Beaman]

Nick is correct in that how Ultra was solved is a very complex matter. It was never consistently solved in the sense that every captured message was solved. This is especially true with German Naval coding.

Much of the initial breakthrough came from manual and primitive computer (these were actually banks of linked enigma machines, endlessly churning through key punched code for common links) analysis as Nick says along with learning how the enigma machine was used and set on a daily basis. Sometimes, rarely, they guessed right, but more often German operators were lazy and used settings that could be seen as repeats or matched up to other known settings and then guessed at. The Luftwaffe was nortorious for:

• Using the radio for almost everything, thus giving more opportunity for the British to see traffic and analyse it for repetitive groups that might be deciphered.
• Using girlfriends names or repeat settings that allowed for deciphering settings on the wheels on a daily basis. I.e., their radio discipline was poor, helping the British.

The German Navy was much more disciplined in changing settings, using random settings and eventually even added more wheels to the machine, making deciphering settings much more difficult. In fact while after 1940 Luftwaffe traffic was deciphered quite regularly, the deciphering the Navy traffic was a hit and miss affair until mid-1943 when the combination of Ultra, Huff-Duff, long range patrol aircraft and the beginnings of the escort carrier deployment finally did in the U-boats.

Ultra is a complex business. There are many excellent books out there, including the ones Nick mentioned. To understand how complex the accomplishment of deciphering was, you almost have to read them all.

[olefebvre]

I recommend having a look at this website :
http://users.telenet.be/d.rijmenants/index.htm
Which at a time ran a challenge of deciphering vintage cripted enigma messages. You'll also find the enigma simulator there if you wish to have some fun with it.

[Tony Jones]

Over the past few months I have been working through HW 5 files at the PRO. there are many instances of "source" reading papers on people's desks and even taking documents out of briefcases, so there were definetely some spies at work here.

Tony

[Nick Beale]

Originally Posted by Tony Jones

Over the past few months I have been working through HW 5 files at the PRO. there are many instances of "source" reading papers on people's desks and even taking documents out of briefcases, so there were definetely some spies at work here.

Tony

Intelligence officers tell lies, it's a big part of the job! If the Germans ever got to see one of the items that are now in HW5 then they would have tied themselves in knots looking for spies in their own ranks while still happily broadcasting in their breakable code.

As I said the front of each file has pages cross-referencing the various messages to the communications nets they were received from (see attached sample) each of which was given a code name by Beltchley Park.

Re John's comment. I saw recently that there is a book coming out from someone who worked on the Luftwaffe traffic at Bletchley:

http://fm.greenhillbooks.com/greenhi...d=33921&-find=

Every other one I've read devotes most space to the U-boat war, so this could be interesting.

[RodM]

Hello One & All,

Nick's answer is ultimately just common sense. The simple fact is that if information was coming via humint it would not need to be decoded at Bletchley Park and would have been processed via other channels.

That is not to say that information from a variety of sources was not analysed to aid the code breakers. As Nick points out, even the decrypted messages weren't neccessarily cleartext and thus messages had to be further decoded. Sometimes the information was on hand to do this, sometimes it couldn't fully be done for weeks (if at all).

In terms of protecting the ULTRA secret, an example is with Operation Gisela; the British first learnt of this operation in December 1944 but it wasn't until after the capture of aircrew personnel who 'spilled the beans' a month later that lower Commands were warned and defensive measures taken.

Cheers

Rod

[Flitzer]

There's another humint that's not mentioned too often, I just ran across a great example today reading Impact - the history of Germany's V-Weapons in World War II.

The following quote is from the book:

"On March 22, 1943, MI recorded a conversation between German Generals Ritter von Thoma and Ludwig Crüwell, who had been captured in Africa. The two men, obviously aware they were being monitored, spoke in hushed tones, and parts of their conversation went unheard even by the sensitive microphones in the room. Crüwell had been captured in May 1942 and von Thoma in November. In bringing Crüwell up to date, von Thoma told of a large rocket he had seen tested, presumably at Kummersdorf, with F.M. von Brauchitsch. The weapon, according to von Thoma, went into the stratosphere and had unlimited range."

And that reminded me of the classic from "The One that Got Away", where the two German POW pilots leaned out of the window to have a discussion -- there was a microphone under the window sill!

[Dennis Peschier]

There seem to be a lot of N.A. research buffs involved in this discussion and I wonder if they can help me with the following; in “Sea Eagles” by Francis L. Marshall the author frequently refers to the British radio interception Service A.I.4. The book gives no source for this information but I think this must be the National Archive in Kew.
One of the things I would be interested in would be the intercepts of Luftwaffe night fighter radio communications for 8/9-3-1945.
I wanted to ask if anyone of you has com across these intercepts an knows in what folder they are stored?

Thanks in advance,

Dennis