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Q: Germans breaking allied crypto codes in WW2 ( Answered 5 out of 5 stars,   1 Comment )
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Subject: Germans breaking allied crypto codes in WW2
Category: Reference, Education and News > General Reference
Asked by: terminus1-ga
List Price: $50.00
Posted: 01 May 2004 13:23 PDT
Expires: 31 May 2004 13:23 PDT
Question ID: 339504
Western allies (especially Brits at Bletchley Park) breaking German
crypto codes of the German mechanical crypto computer "Enigma" were
instrumental to the allied victory in WW2, especially to avoid German
U-boats on the Atlantic to secure convoys securing British Isles with
goods. However I spoke with a historian friend and he said that
Germans were actually breaking Allied codes with similar rate of
success and achieving some of their own success due to that, but this
is much less spoken of. So my question is: did Germans have any
similar facility as the Allies had at Bletchley Park, did they manage
to break any codes with it? If so, what kind? (Army, Navy, ...?) What
impact did this have on the Nazi war effort?
Answer  
Subject: Re: Germans breaking allied crypto codes in WW2
Answered By: scriptor-ga on 01 May 2004 16:03 PDT
Rated:5 out of 5 stars
 
Dear

The German efforts in decryption suffered from a problem typical for
the German armed forces: Numerous branches and institutions maintained
their own cryptology departments, working on their own without
collaborating or sharing results with other similar units. This led,
of course, to unnecessary duplicate efforts, to a fragmentation of
potentials and to a low efficiency. There was no central German
decryption agency like the legendary British Bletchley Park facitlity.
Instead, all these institutions were more or less eagerly engaged in
decrypting:

- Deutsche Reichspost (DRP, Reich Mail Service)
- Forschungstelle (Research Bureau, telephone intercept unit, part of the DRP)
- Forschungsamt (Research Office, under the authority of Reichsmarschall Göring)
- Auslandsamt, Abteilung Z 
- Oberkommando der Wehrmacht/Chiffrierungsabteilung (OKW/Chi -
Wehrmacht Supreme Command/Decryption Department)
- Oberkommando des Heeres/Abt. Fremde Heere Ost (OKH/FHO - Army
Supreme Command/Foreign Armies East Dept.; intelligence focussed on
Eastern nation's armies)
- Oberkommando des Heeres/Abt. Fremde Heere West (OKH/FHW - Army
Supreme Command/Foreign Armies West Dept.; intelligence focussed on
Western nation's armies)
- Oberkommando der Wehrmacht/Abwehr (OKW/Abwehr - Wehrmacht Supreme
Command/Counterintelligence)
- Oberkommando der Luftwaffe (OKL - Air Force Supreme Command)
- Oberkommando der Marine (OKM - Navy Supreme Command)
- Reichssicherheithauptsamt (RSHA - Reich Security Main Office)


While most of these institutions did not contribute much to the German
war efforts, the Navy's OKM had some remarkable successes in breaking
allied codes. The 2. Abteilung der Seekriegsleitung included the
Marinenachrichtendienst (M.N.D.) and its III. Abteilung, radio
intelligence. The B-Dienst (Beobachtungsdienst, surveillance service)
and the xB-Dienst (decryption service) were able to decipher quite
much of the encrypted Allied radio communication.

The B-Dienst, created in the early 1930s, had decrypted the most
widely used code of the British Navy already by 1935. When the war
broke out in 1939, the B-Dienst specialists had deciphered the British
naval codes so well that the Germans new the positions of all British
warships. They had further decryption successes in the early stages of
the war; the British were slow at changing the codes. One important
code the B-Dienst could read was the British and Allied Merchants
Ships (BAMS) code, which proved valuable for U-Boat warfare. In
February 1942, the B-Dienst cracked the code used for communication
with many of the Atlantic convoys.

Before the USA entered the war, the B-Dienst could decipher various
American code systems. This was not the case anymore after April 1942,
when the USA changed their code systems; before that, however, the
capability of understanding the American encoded messages contributed
to the success of "Operation Paukenschlag", the massive wave attacks
of U-Boats off the American East Coast in early 1942.

In 1941, the US Navy refused for security reasons to equip the British
Navy with their EMC Mk.1 encryption devices, so the British Admirality
introduced the "Naval Cipher No.3" for Allied radio communication and
convoy coordination in the Atlantic. The B-Dienst concentrated on
deciphering the new code, and though it took a while, they finally
were successful in September 1942: From December 1942 to May 1943, 80
percent of the intercepted radio messages were decrypted. However,
only 10 percent of them were decrypted in sufficient time to take
effective action.

The British "Naval Cipher No.5" is also known to have been cracked by
the B-Dienst, as were various low-grade British Naval and Air codes,
including COFOX, MEDOX, FOXO, LOXO, SYKO, Air Force code and Aircraft
Movement code; the US "Hagelin" encryption; the French "Anglp" code.

In addition to those activities, the B-Dienst also cracked Soviet and
Danish code systems.


Apart from the notable successes of the Navy's decryption services,
there were also some results from the other institutions. For example,
the Reichspost was able to descramble the scrambled voice transmission
of the transatlantic telephone conncection between the USA and Great
Britain. For this purpose, an interception and descrambling facility
was built in Noordwijk, occupied Holland. From 1940, the Mail
Service's descrambling specialists intercepted and understood
classified telephone conversation between President Roosevelt and
Prime Minister Churchill. After the facility had to relocate to
Germany in 1944, the interception potential grew smaller, and so did
the number of phone calls intercepted. But this was not so much
classic codebreaking than rather development and utilization of
sophisticated technology.

Another success was that the OKW/Chi cryptoanalysts had in 1941
cracked the "Black" code used by US diplomats. Due to this, a huge
interception facility in Lauf/Bavaria could decrypt communication
between US diplomats and Washington DC. The specialists in Lauf
concentrated on the messages relating to the African theater of war,
so they could supply Feldmarschall Erwin Rommel with valuable
information on Allied plans and operations. It is a noteworthy
footnote that the Germans also received the "Black" code from the
Italians: Italian spies had photographed the code tables in the US
embassy in Rome in September 1941. While the Germans appreciated this
gift from their ally Italy, they did not let them know that they were
already able to decipher "Black" code messages.

Generally speaking, however, German performance in codebreaking was
weak due to the incredible fragmentation of competencies and
specialized personnel. The Navy's B-Dienst makes the exception from
the rule, though its great time was over when the Allies started using
more sophisticated encryption methods by 1943.


Sources:

Feldgrau.com: German Code Breaking of WWII, by Arvo Vervcamer
http://www.feldgrau.com/articles.php?ID=12

Suite101: Too Close For Comfort: Britain, Ultra, and the Battle of the
Atlantic (1941-43), by Joseph Sramek
http://www.suite101.com/article.cfm/british_history/9964

About.com: A Secret Ear for the Desert Fox
http://africanhistory.about.com/library/prm/bldesertfox1.htm

HyperWar Foundation: Compromise of Allied Codes and Ciphers by German
Naval Communication Intelligence
http://www.ibiblio.org/hyperwar/ETO/Ultra/SRH-009/SRH009-6.html

The Journal of Intelligence History: Volume 1, Number 1, Summer 2001
http://www.intelligence-history.org/jih/reviews.html

9te U-Flotille: Lexikon - B
http://www.9teuflottille.de/site/lexikon/details/lexikon_b.html

Chronik des Seekrieges 1939-1945: 1941 - Juni
http://www.wlb-stuttgart.de/seekrieg/41-06.htm



Search terms used:
abwehr cryptanalysts
://www.google.de/search?q=abwehr+cryptanalysts&ie=UTF-8&oe=UTF-8&hl=de&btnG=Google-Suche
"OKW/Chi"
://www.google.de/search?q=%22OKW%2FChi%22&ie=UTF-8&oe=UTF-8&hl=de&btnG=Google-Suche
okm "b dienst"
://www.google.de/search?q=okm+%22b+dienst%22&hl=de&lr=&ie=UTF-8&oe=UTF-8&newwindow=1&start=0&sa=N
"b dienst"
://www.google.de/search?q=%22b+dienst%22&hl=de&lr=&ie=UTF-8&oe=UTF-8&newwindow=1&start=10&sa=N
"german cryptanalysts"
://www.google.de/search?q=%22german+cryptanalysts%22&ie=UTF-8&oe=UTF-8&hl=de&btnG=Google-Suche
codebreaking abwehr
://www.google.de/search?q=codebreaking+abwehr&hl=de&lr=&ie=UTF-8&oe=UTF-8&newwindow=1&start=70&sa=N
rommel "black code"
://www.google.de/search?hl=de&ie=UTF-8&oe=UTF-8&newwindow=1&q=rommel+%22black+code%22&btnG=Suche


Hope this is what you needed to know!
Best regards,
Scriptor
terminus1-ga rated this answer:5 out of 5 stars
An exhaustive and informative overview. Gave me the all info I was
looking for and more. Thanks!

Comments  
Subject: Re: Germans breaking allied crypto codes in WW2
From: probonopublico-ga on 01 May 2004 21:28 PDT
 
Fascinating, Scriptor, I have never seen the information presented so well.

It has been said that the British & French campaign to invade (sorry I
should have said 'assist') Norway in April 1940 was ruined because the
British Naval Codes had been cracked by the Germans (per David Kahn).

Your Answer gives this substance.

Great stuff!

Bryan

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