(1/12) World War II Mind of a Code Breaker

World War II Videos
During the two years of the war, British cryptologists decoded German communications with limited success. Older codes, used for low security messages, were readily identified and broken by the Bletchley Park team. Some newer codes were broken mathematically, but decoding and translating these messages by hand proved an arduous task. By the time messages were fully understood, the information they contained was often outdated. Compounding the problem, these intercepts contained very little useful intelligence information. Since the mid-1930s, the German government had used complex cipher machines to disguise their most important communications.
The first great code breaking triumph at Bletchley Park came on August 30, 1941. A British "Y Station," one of the military listening stations that intercepted German communications, picked up a depth, a repeat transmission that used the same settings on the cipher machine. This intercept was forwarded to Bletchley Park. Cryptologists identified as "fish," the nickname for a message produced by the illusive Geheimschreiber cipher machine. Within two months, the Bletchley Park team broke the high-level German code.
To facilitate the processing of "fish" intercepts, Bletchley Park engineers borrowed an idea from plans the Polish intelligence service gave Britain before the war. They constructed a machine that aided the deciphering of intercepts, nicknamed a "bombe" because of the low, roaring noise it made while operating. The "bombe" constructed to decipher Geheimschreiber transmissions did help cryptographers to process intercepts more rapidly, but the machine required the exact synchronization of two paper tapes for printing. The tapes often broke, and the machine had to be reset. In addition, the start setting to process each intercept, the original cipher settings used by the Germans to send the message, had to be calculated by British cryptologists by hand. The process was still too complex to yield decoded intercepts ready for immediate translation to be useful to intelligence and military personnel.
Most of Germany's high-level military messages were encoded using a cipher machine called Enigma. The complex code used not only a cipher, but also an overlaying encryption to disguise the original text. The series of rotor wheels on the Enigma teleprinter gave the machine an extraordinary number of code combinations. The Germans were so confidant that the machine code was so nearly infinite in possibilities that it could never be broken. However, various intelligence services in neighboring nations had made considerable progress breaking Enigma even before the outbreak of the war. In Britain, efforts to break Enigma were known as Operation Ultra.
In the months preceding the German invasion of Poland in 1939, Polish intelligence passed on to British intelligence information on their efforts to break Enigma. Most helpful was the information Polish spies gathered on how the cipher machine operated, including sketches of the teleprinter and some of its components. With the information, Bletchley Park cryptologists found two key weak links in the Enigma code. Enigma code prohibited that any letter be encrypted as itself, and German standards of communication dictated that the same phrase begin all transmissions. Exploiting these two weaknesses, British cryptologists unraveled the Enigma code mathematically in late 1940.
Even though cryptologists could read portions of Enigma transmissions, they encountered the same delay of accessing intercepted information as they had with other codes. Another bombe was constructed that could process Enigma codes, expediting code breaking. However, cryptologists and engineers at Bletchley Park realized that another mechanical solution was needed to fully exploit German intercepts. To this end, two Bletchley Park engineers invented Colossus, the first electronic, programmable machine in 1943. Colossus not only decoded messages, but also broke through the overlaying cipher, producing a ready to translate copy of the intercept in the original German. With Colossus, Bletchley Park could decipher German communications before the intended recipients. Translated intercepts were immediately passed on to intelligence and military officials, making Bletchley Park central to the Allied war effort.

Category:

Education

Tags:

• World
• War
• II
• Enigma
• Bletchley
• Park
• British
• German
• Poland
• Polish
• Colossus
• Alan
• Turing

[uka79]

Rejewski broke the military Enigma (plugboard version) in 1932. He used a theorem on permutations to solve it. Along with his friends between 1932-1939 they designed mashines to facilitate and speed up the process of decrypting. Among others they designed a device called Rejewski Bomb. To brake the 1938 version of Enigma you had to take several RB and make them work in parallel. This is what Turing did creating Turing Bomb.

[2bn442RCT]

@uka79 Thanks for your imput!

[landen99]

It is good to recognize the contributions of the Poles in attacking the Enigma machine with replicates and deciphering messages using replicas and weak keys. Also good to remember that some of the Polish codebreakers fled to France and then to England to join the British codebreakers there and add their (promptly classified) experience and knowledge.

[2bn442RCT]

@landen99 They deserve credit

[Plattythegreat]

This Programme is just a re-edited and re-narrated version of the british channel 4 programme called 'Station X', Made by Darlow-Smithson productions in 1999.

[2bn442RCT]

@Plattythegreat Where can I find that.

[dehmeldehmel]

What about the Polish scientists who lost their lives delivering half of the job already Done to he guys Bletchley??

Anyway, Thank EDUCATION for all of them (Poznan's and Bletchley Park Scientists)

[mufc99ok]

THIS JUST FANTASTIC STUFF

[uka79]

@kdr0

For more information I would refer you to Rejewski papers published and translated into English many many years after war. If you take into account the state of the pre-war cryptography you will understand why the British and the French were clueless before the meeting in Pyry.

[uka79]

@kdr0

This is why Bletchley Park succeeded so fast. Even though the Poles were the first to break Enigma during wartime, the method (Zygalski's sheets) they had to use because of technical limitations (they were operating in the occupied France, for some mysterious reason they were not in Blechley!!) soon proofed to be obsolete (after consecutive modifications).

[uka79]

@kdr0

But they were able to read it before the war as well (the machine was less complicated then). What is even more impressing they reverse-engineered the wirings in the military version's rotors without having access to the machine. They were technically unable to read it after the modifications introduced in 1938 – they only managed to design appropriate devices. These plans along with theoretical background were then transferred to the French and the British (secret meeting in Pyry).

[kdr0]

@uka79

Not entirely true. Poles were the first to read Enigma ciphertext during wartime (precisely on Jan 17, 1940).

[kdr0]

@2bn442RCT

Ok, let's get the facts right. Where did you get this video description from? It contains a number of historical inaccuracies (like the myth about Polish spies).

[debzeppeliniv]

the Polish people were in bondage for almost 60 yrs, first the Nazis then the communists. I went to school with them all my life and there were very few dumb polocks, bless those poor people I am so glad they are finally free, we need their brain power.

[Flickchaser]

Thnx for post-one of the most interesting on YT. I believe National Cash Register was involved in manufacture of deciphering equipment here in U.S. during WWII but have not seen any clip or books to confirm.

[Emporator]

There's a snippet of background music played from time index 6:13 to 6:37 - I don't suppose anyone knows this piece of music?