Figure 1.--These are the major links and staions of the German Lorenz network. It was much smaller than the Enigma network is is the major German Lorez network because it only connected headquarters. There were other links, but these were the major ones. Notice the use of the fish names. The Lorebz system was begun (June 1941). It varied along with Germnan mikitar success. This looks like the situation about January 1943. Source: Copeland.

Enigma was not the only major German cipher system with which the Allies had to conted. The German High Command (OKW) asked the Lorenz company to build a high security teleprinter cipher machine to give them the ability to send and receive radio messages in absolute secrecy. This was a system even more secure than the Enigma machines. The Lorenz company came up with a cipher machine based on modular arithmatic. [MacCallum] It employed the additive method for enciphering teleprinter messages. The system has been invented by an American, Gilbert Vernam (1918). Teleprinters are not based on the standard 26-letter English alphabet (which is very similar to the German alphabet) and Morse code on which the Enigma machines are based. Rather teleprinters use the 32-symbol Baudot code. This consists of five channels each of which is a stream of bits which can be represented variously as no-hole or hole, 0 or 1, dot or cross. Thus, the many rotors and other complicatins the Grrmans devised meant that the Lorenz code presented an a complexity an order of magnitude deyond that of Enigmam. It was the most sophisticated and complex of the Axis code systems. And caried the most secret German messages. Enigma was more housekeeping messages for the German miliarry. Bletchly had to piece the many disparate messages together to get insights into German operations. Lorenz carried actual messages dealing with German strategy, messages between OKW (which involved Hitler himself) and the major far-flung German command posts. The British called it Tunny. There were a fairly small number of stations for sending and receiving Lorenz messages. Berlin and Könningsberg were at the heart of it. Each link in the system had a fish name, the overall name was called Tunny. Incredably Bletchely code breakers were able to crack Lorenz with raw brain power. Cracking Enigma was aided by the Poles who built machines as well as actual German Enigmas and code books which the British captured. The Lorenz team had nothing to work with other than Y-Service intercepts. And as the intercepts were not in Morse code. Lorenz was a huge challenge from the beginning. Incredably two working class scholarship boys not only cracked it, but developed an automated process for decyphering the transmissions, essential in real time. John Tiltman sussed out that it was a Vernam cipher and cracked early versions. Bill Tutte, who Turing turned down for his Enigma team, played a key role in solving the the more advanced versions. As with Enigma, German operational shortcomings, opeartors not following procedures, played a key role in the British success. The problem for the British was that it was a laborious process, especially as the Germans kept adding complications. Here Tommy Flowers, another schlarship boy, delivered the coup de grace. He automated the process. His idea was at first dismissed and he had to use his own money. His process was eventually recognized and he created the first electronic computer--Colossus (December 1943). This mnean that the Allies as preparations for D-Day began had a direct look into Hitler's mind that Enigma did not provide. All of this was done without ever seeing a Lorenz machine until the last months of the War. It was all a matter of virtulaly unbelievable raw genius. The Soviets presumably acquired Lorenz machines much earlier than the Allies. We have no idea what they did with the Lorenz machines they much have acquired during their various offensive operations. Soviet/Russian historians have not addressed this matter.

Lorenz System

Enigma was not the only major German cipher system with which the Allies had to conted. The German High Command (OKW) asked the Lorenz company to build a high security teleprinter cipher machine to give them the ability to send and receive radio messages in absolute secrecy. This was a system even more secure than the Enigma machines. The Lorenz company came up with a cipher machine based on modular arithmatic. [MacCallum] It employed the additive method for enciphering teleprinter messages. The system has been invented by an American, Gilbert Vernam (1918). Teleprinters are not based on the standard 26-letter English alphabet (which is very similar to the German alphabet) and Morse code on which the Enigma machines are based. Rather teleprinters use the 32-symbol Baudot code. This consists of five channels each of which is a stream of bits which can be represented variously as no-hole or hole, 0 or 1, dot or cross. Thus, the many rotors and other complicatins the Grrmans devised meant that the Lorenz code presented an a complexity an order of magnitude deyond that of Enigmam. Lorenz was different than Enigma because the machine settings (indcator keys) were mostly part of the encrypted settings.

Importance

Lorenz was the most sophisticated and complex of the Axis code systems. And caried the most secret German messages. Enigma was more housekeeping messages for the German military. Bletchly had to piece the many disparate messages together to get insights into German operations. Lorenz carried actual messages dealing with German strategy, messages between OKW (which involved Hitler himself) and the major far-flung German command posts. The British called it Tunny.

Network

There were a fairly small number of Lorenz stations for sending and receiving Lorenz messages. Berlin and Könningsberg were at the heart of the system. Könningsberg was impottant because it was close to te Wolf's Lair (Wolfsschanze). It was Hitler's top-secret and most important Central and Eastern Europeheadquarters. It was located in the Masurian woods about 8 kilometres east of the small East Prussian town of Rastenburg. It was built for the launching of Operation Barbarossa (June 1941). He would spend more than 800 days there during the War. It was there that the nomb plotbassasination nattemp occurred (July 1944). Each link in the Lorenz system was assigned a fish name by the British, the overall name of the system was called Tunny. The first Tunny link was between Berlin and Salonika/Athens was established on an experimental basis (June 1941). The next link was between Königsberg and South Russia as Barbarossa unfolded. At the time of the D-Day invasion (June 1944), the British had detected 26 different links. [Copeland]

Cracking Lorenz

Incredably Bletchely code breakers were able to crack Lorenz with raw brain power. Cracking Enigma was aided by the Poles who built machines as well as actual German Enigmas and code books which the British captured. The Lorenz team had nothing to work with other than Y-Service intercepts. And as the intercepts were not in Morse code. Lorenz was a huge challenge from the beginning. As with Enigma, German operational shortcomings, opeartors not following procedures, played a key role in the British success. The problem for the British was that it was a laborious process, especially as the Germans kept adding complications. Col. John Tiltman sussed out that Lorenz was a Vernam cipher. Progress began with the Tiltman Break. A German operator had to retransmit a long message. Lorenz messages tended to be longer than the Enigma messages. Bletchely called the two nearly identical messages a 'depth'. The operator violated security protocols by using the same key settings (indicators). Col. John Tiltman using the additive method was able to decrypt the two messages and used the insights gained to decrypt other depths. His procedures decrypting messages by hand, however, were laborious. [Copeland] And as the Germans added complications, virtually impossible. Two working class scholarship boys not only cracked it, but developed an automated process for decyphering the transmoissions, essential in real time. Bill Tutte, who Turing turned down for his Enigma team, played a key role in solving the the more advanced Lorenz transmissioins. But again the process was labrious. Here Tommy Flowers, another schlarship boy, delivered the coup de grace. He automated the process. His idea was at first dismissed and he had to use some of his own money. His process was eventually recognized and he created the first electronic computer--Colossus (December 1943). This mneant that the Allies as preparations for D-Day began had a direct look into Hitler's mind that Enigma did not provide. All of this was done without ever seeing a Lorenz machine until the last months of the War. It was all a matter of virtulaly unbelievable raw genius. By the end of the War, Bletchely had 10 Colossus computers working on Lorenz messages.

Soviets Capture Lorenz Machines

The Soviets presumably acquired Lorenz machines during the War. Bletchely never saw a Lorenz Machine duriung the War. They built machimes based on thrir cracking operations. Although there were much smaller numbers of Lorenz machines and stations than Enigma machines, so perhaps the Soviets never got a hold of one. We have no idea what if anything they did with the Lorenz machines they may have acquired during their various offensive operations. Soviet/Russian historians have still not addressed this matter. The reason that Churchill did not order all the Colossus computers destoyed is that he though that the Soviets might have secured some Lorenz machines and use them. Thus some of the Colossus computers might prove useful in the Post-War era.

Value

Coming from Germam headquaters, these messages were very valuable. In fact many were from Hiter's headquaters (Berlin or the Könningsberg/Wolf's Lair). Some were signed by Hitler himself. This meant they were of great straegic value. The Allies intercepted 27,631 Lorenz messages and dechiphered about half--13,508. The Allies were able to warn Stalin of Hitler decision to strike at Kursk. There is ni way of knowing that this was the cfirst indicator, but in espionage even warnings confirming other sources are of great value. Decrypts showed that the Allied disinformation campaigns had cofused the Germans when the only reasonable target after the Allied victory in Tunisia was Sicily. And confirmed that the Italian campaign while progressing skowly was successfuly tying down German forces. Decrypts provided information on German dispositions and assessments before D-Day. This include the all inportant details on the Panzer divisions. It showed that the Germans were falling for the FUSAG deceotion with Panzer divisions concentrated in the Pas de Calis area.

Cracking Soviet Codes

TICOM (Target Intelligence Committee) was a secret Allied project ininited by the British at the end of World War II to find and seize German intelligence assets. They were especilly interested in cryptology and signals intelligence. [Rezabek] The most nptable TICOM sucess was to capture German wide-band receivers that were being used to intercept Soviet high-level radio teletype signals. A TICOM Team 1 unit (Lorenz recovery) group learned thzat a German POW knew about signals intelligence equipment and documentation used for Soviet intercepts May 21, 1945). Other Germans wotking at the unit were udentifyined and takebn to therir base at Rosenheim. They recovered about 7 ½ tons of communications equipment. The German POWs reassembled one of the machines and demonstrated low it wirked. TICOM officer 1st Lt. Paul Whitaker reported, "They were intercepting Russian traffic right while we were there … pretty soon they had shown us all we needed to see." [TICOM]

Sources

Copeland, Jack. "Colossus: Breakong the German 'Tunny' Code at Bletchely Park. An Illustrated History," Rutherford Journal.

Gannon, Paul. Colossus: Bletchley Park's Greatest Secret (Atlantic Books: 2006).

MacCallum, Malcolm A.H. "WW II code beaking and the first computers, " Copernicus Festival (May 28, 2014).

Rezabek, Randy. TICOM: the Hunt for Hitler's Codebreakers (Independently published: 2017).

Singh, Simon. The Code Book: The Science of Secrecy from Ancient Egypt to Quantum Cryptography (Knopf Doubleday Publishing Group: 2011)

TICOM. Team 1 Report Appendix 14. Baudot Equipment Report on Gen Der Nach. Aufkl. Gruppe VI.

Created: 5:19 AM 7/28/2020
Last updated: 11:08 PM 7/18/2021