Tuesday, September 1, 2015

New reports released by the NSA

Even though most TICOM reports have been released by the NSA and GCHQ, some are still classified. It seems that (finally…) this is beginning to change since I just received TICOM I-89 ‘Report by Prof Dr. H Rohrbach of Pers Z S on American strip cipher.

This was a report prepared in August 1945 by the mathematician dr Hans Rohrbach. During WWII Rohrbach was one of the top cryptanalysts of the German Foreign Ministry’s decryption department Pers Z. His major success was the solution of the M-138-A strip cipher system used by the US State Department for its most important messages.
The report details the mathematical method of solution and the use of a special device, called the ‘Automaton‘, that could quickly decode the messages once the alphabet strips and keylists had been reconstructed.

When i requested this report in 2013 the NSA’s response was: ’We have completed our search for records responsive to your request. We located item 1 of your request. That document was reviewed in 2006 and was witheld in full. The document requires a new review to determine whether any of it can be released at this time.‘
Based on this response i was expecting that I-89 would contain fascinating details about the work of the German codebreakers. Unfortunately after going through the report it’s clear that it is the same report submitted by Rohrbach to the FIAT Review of German Science in 1948 and also published in the journal Cryptologia in 1979.

My other request to the NSA was for page 92 of the Special Research History SRH-366 'History of Army Strip Cipher devices'. Some of you may have noticed that it is missing a page. In any case here it is:

Again it doesn’t seem to contain groundbreaking information. What can I say, you win some you lose some….

Monday, August 10, 2015


1). I’ve added links to Allied agents codes and Referat 12 in several essays dealing with agents codes.

2). In The US AN/GSQ-1 (SIGJIP) speech scrambler I had written ‘The US authorities used up to mid 1943 the Bell Labs A-3 speech scrambler, a device that utilized speech inversion’. This was not correct, as the A-3 used band-splitting and inversion.
3). In WWII Myths - T-34 Best Tank of the war I added a new link to the report Evaluation of tanks T-34 and KV by workers of the Aberdeen testing grounds of the US, as the old one was not working.

4). In Enigma security measures I added information from the report ‘Änderungen beim Schlüsseln mit Maschinenschlüssel’ in paragraphs Random indicators and CY procedure.

Sunday, August 2, 2015

Allied agents codes and Referat 12

In the course of WWII both the Allies and the Axis powers were able to gain information of great value from reading their enemies secret communications. In Britain the codebreakers of Bletchley Park solved several enemy systems with the most important ones being the German Enigma and Tunny cipher machines and the Italian C-38m. Codebreaking played a role in the Battle of the Atlantic, the North Africa Campaign and the Normandy invasion. 

In the United States the Army and Navy codebreakers solved many Japanese cryptosystems and used this advantage in battle. The great victory at Midway would probably not have been possible if the Americans had not solved the Japanese Navy’s JN25 code.
On the other side of the hill the codebreakers of Germany, JapanItaly and Finland also solved many important enemy cryptosystems both military and diplomatic. The German codebreakers could eavesdrop on the radio-telephone conversations of Franklin Roosevelt and Winston Churchill, they could decode the messages of the British and US Navies during their convoy operations in the Atlantic and together with the Japanese and Finns they could solve State Department messages (both low and high level)  from embassies around the world.

Radio intelligence and codebreaking played an important role not only in the military and diplomatic fields but also in the shadow war between the Allied intelligence agencies, the European Resistance movements and the German security services. In the period 1939-41 German troops conquered most of continental Europe and the occupied countries were forced to contribute to the Axis effort by sending raw materials, agricultural products and forced labor to Germany. Thanks to the blockade of German occupied Europe by the Royal Navy and the harsh demands of the German authorities life in the occupied areas was bleak. Discontent over German occupation led many people to join resistance movements and oppose the authorities, either by printing and distributing anti-Axis leaflets and books, by sabotaging war production or by directly attacking the German troops and their collaborators in the government and the civil service.