Update

I’ve added information from a report titled ‘Penetration and compromise of OSS in Switzerland and Western Europe’ in Allen Dulles and the compromise of OSS codes in WWII.

I’ve also located a very interesting report on tank warfare during the Korean War. There is information on the performance of the T-34 tank from US reports and N. Korean POW interrogations. It seems the T-34/85 had serious shortcomings in Korea…I’ll write more about this in the future.

Codebreaking software for classical ciphers

If you like playing around with codes and ciphers the CryptoCrack program created by Phil Pilcrow might be worth checking out. It’s free and can be downloaded here.

More information on Office of Strategic Services and Office of War Information cryptosystems

In my essays Compromise of OWI - Office of War Information communications and Allen Dulles and the compromise of OSS codes in WWII i’ve looked into the compromise of OSS and OWI communications in WWII. Unfortunately it is very difficult to find detailed information on the cryptosystems used by these organizations in WWII but a report found in SRH-145 ‘Collection of memoranda on operations of SIS intercept activities and dissemination 1942-45’, dated 16 October 1943 says that they used cipher machines and hand systems (M-138 strip cipher and double transposition).

I’ve added this information in the aforementioned essays.

Acknowledgements: I have to thank Rene Stein of the National Cryptologic Museum for sending me SRH-145.

Update

I have added new messages in Compromise of OWI - Office of War Information communications.

For Victor from Burns

In the period 1942-45 the Office of Strategic Services station in Bern, Switzerland (headed by Allen Dulles) collected information from occupied Europe and transmitted intelligence reports back to Washington. Some of these reports were decoded by the German and the Finnish codebreakers.

The following message can be found in the Finnish national archives. The original was copied from NARA, collection RG 59.

 

 

‘Umberto’ may have been Crown Prince Umberto of the House of Savoy.

I have added this message in Allen Dulles and the compromise of OSS codes in WWII.

Update

I have added information from the War diary of Inspectorate 7/VI and KONA 4 in The secret messages of Marshall Tito and General Mihailović.

Not quite true…

During WWII the top Allied officials in the US and the UK frequently communicated via a radio-telephone link protected by the Bell Labs A-3 speech scrambler. This device was not secure enough to be used at such a high level but since no other alternative was available it was used extensively by military personnel, diplomats and even Roosevelt and Churchill.

In order to secure these sensitive communications the Americans designed and built the Sigsaly device. The NSA website says about Sigsaly:

‘The SIGSALY system was inaugurated on 15 July 1943 in a conference between London and the Pentagon (the original plan had called for one of the terminals to be installed in the White House, but Roosevelt, aware of Churchill's penchant for calling at all hours of the night, had decided to have the Washington terminal moved to the Pentagon with extensions to the White House and the Navy Department building.) In London, the bulk of the SIGSALY equipment was stored in the basement of Selfridges Department Store, with an extension to Churchill's war room, approximately a mile away……….. With the coming of SIGSALY, the shortcomings of the less than effective A-3 were now a thing of the past’. 

This doesn’t appear to be the whole truth. While it is true that the system was installed in July 1943 it didn’t work properly till late 1943 and it only become fully operational in April 1944. Even after it was installed officials continued to use the A-3 for most of their communications since the only Sigsaly link was available at the Cabinet War Rooms and only a small number of officials had authorization to use it.

This information comes from the book ‘The woman who censored Churchill’, p112-3. I’ve added this information in Intercepted conversations - Bell Labs A-3 Speech scrambler and German codebreakers and German intelligence on operation Overlord.

Update

I have added information in:

Swedish Army codes and Aussenstelle Halden

Wartime exploitation of Turkish codes by Axis and Allied powers