Who solved the Enigma code. Enigma was a legendary cipher machine. Its hack saved thousands of lives. Who invented Enigma

The legendary Enigma encryption machine has become a symbol of spy stories during the Second World War. According to various estimates, hacking it shortened the war by two years and saved millions of lives. This is the story of how Britain's best cryptanalysts, armed with mathematical tools, were able to decipher the most complex German code.

​The birth of a legend

Cryptanalysis- the science of methods for deciphering encrypted information without using the original key. Cryptographers, on the contrary, are engaged in encrypting texts and other data.

Paradoxically, the Enigma encryption machine was not created for the military, but to classify business negotiations. The device was developed and patented in 1918 by a German engineer. Arthur Sherbius. The Enigma of the first series weighed more than 50 kg. Due to the high cost and complexity of use, the encryption machine did not initially attract the attention of buyers. For five years, Scherbius managed to sell only a few copies for the needs of foreign armies and communications companies.

Arthur Sherbius

Inventor of the Enigma encryption machine, which means “riddle” in Greek. In 1908 he graduated from the University of Hanover, and ten years later he organized the private company Scherbius and Ritter, which produced Enigma. The inventor did not live to see the triumph of his brainchild - he died in 1929 as a result of an accident.

The encryption machine was highly appreciated by the German army. In 1925, it was adopted first by the Navy (model Funkschlussen C), and in 1930 by the Wehrmacht (Enigma I). The total number of encryptors produced before and during World War II exceeded 100 thousand. They were used by all types of armed forces of Nazi Germany, as well as military intelligence and security services.

Enigma ciphers

The operator encrypted the message using a code book. The entries in it looked like this:

We see installations on the 31st day of the month (the code changed every day). The operator must select reflector B, set the letters C, T and R on the rotors IV, I, VII, respectively. The following is the procedure for closing the contacts on the cross-panel. When encrypting, the operators followed the general rules: there are no spaces, punctuation marks are indicated by symbols (for example, a comma is YY, and quotation marks are X). In addition to the day code, each message had its own key (the position of the rotors), which was sent in encrypted form along with the text of the message.

What was this car? The design is based on 3 rotating drums (disks) with 26 electrical contacts on each - according to the number of letters of the Latin alphabet. With these contacts, the drums came into contact with each other and ensured the passage of an electrical impulse. Letters were applied to the ends of the contacts. Before starting work, the operator set a code word on all three reels and typed text on the keyboard. Each disk was responsible for a basic encryption step - replacing one letter with another, for example P with W. Three disks made the encryption logic much more complicated. Each key press caused an electrical impulse, which, passing through the drums, turned the first disk one step. After the first drum made a full revolution, the second came into play, then the third - it was like the operation of an electric meter.

The electrical signal, passing through the drums, entered the reflector of the encryption machine. It consisted of 13 conductors, which were pairs of contacts on the back of the third disk. The reflector sent an electrical signal back to the drums, but along a new path - this significantly complicated the encryption mechanics. Next, the electrical impulse lit one of the indicator lamps, which showed the letter of the encrypted text.

Encryption device M-94

On the first versions of Enigma, three people usually worked at once: one read the text, the second typed it on the keyboard, and the third read the text from the indicator lights and wrote down the encrypted message. The machine had one fundamental flaw - the inability to encrypt a letter through itself. That is, for example, L could be encrypted with any letter of the alphabet, except, in fact, L. Later, this became one of the most important clues that led to the breaking of the cipher.

How does Enigma work?

Rotary discs. The heart of Enigma is disks with 26 contacts on each side. The input and output contacts were connected randomly. Passing through the rotor, the signal was converted from one letter to another.

Reflector had 26 contacts and was connected to the third rotor. It “reflected” the current from the third rotor and sent it back, but along a different path. The reflector ensured that no letter would be encrypted through itself.

Display panel had 26 light bulbs and repeated the layout of a mechanical keyboard. It served as an indicator of the output letter during the encryption process.

Switch. Under the Enigma switch there was a compartment with a 4.5 volt battery.

Keyboard included 26 characters: from A to Z. It had no numbers, no commas, no spacebar. Punctuation marks were replaced by conventional symbols (for example, comma - YY). The numbers were written in words.

Cross panel. It was present in military models of Enigma and was a set of sockets for plugs. Served to swap the contacts of two letters whose plugs were currently connected.

​Battle on the radio

Three people worked on the first versions of Enigma: one read the text, the second typed it on the keyboard, the third wrote down the encryption

Germany in the early 1930s was actively arming itself and preparing for war. Particular attention was paid to deep secrecy when transmitting information via radio channels. Therefore, all Enigmas worked under conditions of secrecy: for each session of the encryption machine there were day keys (a set of letters indicating the initial position of the rotors), identical for the transmitter and receiver machines. Each cryptographer had a special notebook with hundreds of keys for each broadcast. Before sending a message, the operator came up with a new key for this message and encrypted it. Let's say the day key is AOH. The operator and the recipient set AOH on their rotors. Next, the operator encrypts the key to the message twice. Let's say he chose the EIN key. As a result of entering the EINEIN key twice, XHTLOA was displayed in the cryptogram. Next, the text was typed, encrypted using the EIN key. The recipient of the message entered the first 6 letters and decrypted the key - the initial position of the rotors for this message.

The situation was complicated by the fact that the Germans encrypted no more than 250 characters at a time, and a few years later they added two more reels. This significantly increased the resistance of the ciphers to cracking. The senior command staff used Enigma II for some time, consisting of eight rotors at once. However, due to the complexity of the work and low reliability, it was soon abandoned.

Sometimes the Germans deliberately littered the radio space: “Enigma” sent incoherent, meaningless scraps of phrases onto the air. We can say that German signalmen used a spam attack for the first time. All these measures undoubtedly complicated the work of European intelligence services to decipher the codes of the Third Reich.

"Wolf Packs" Dönitz

The ruthless submarine war waged by Nazi Germany left little chance for the commercial and military ships of the USSR, Great Britain and the USA. The main means of communication for Kriegsmarine submarines was the naval version of Enigma. With its help, the leadership organized strike groups of submarines and directed them towards convoys with the aim of destruction. Such a “wolf pack” attacked ships exclusively in a group and pursued dozens of miles, sending several ships to the bottom. One of the inspirers of this tactic was the commander of the German submarine fleet, Karl Dönitz. With the deciphering of the Enigma codes, the British began to receive accurate information about the location of enemy ships and their intentions - luck turned away from the “wolf packs”.

Intercepting the radiogram was not enough to decipher the message. Intelligence services helped. At the end of the 20s, a Polish group of cryptanalysts received a commercial version of Enigma. This allowed us to get a general idea of ​​the logic of the encryption machine. A few years later, French intelligence was able to obtain an operating manual for the latest military model. However, all this only helped to understand the principle of operation of the device - it was still impossible to decipher the messages.

The Art of Cryptanalysis

A classic decoding technique is frequency analysis. The idea is that the frequency of occurrence of a certain letter or even a syllable in a long text is the same in any language and cipher. This makes it quite easy to solve codes created by replacing letters in the text - just reverse substitution. Enigma-type rotary cipher machines were much more resistant to crypto-cracking because they reduced the number of repeating sequences, which made frequency analysis powerless. Nowadays, cryptanalysis is based on the enormous computing power of computers and is widely used by private corporations, intelligence agencies and hackers.

The luckiest ones at this stage were the Polish cryptanalysts. Having gained access to the entire array of European intelligence data, they were able to read German encryption from 1933 onwards. This lasted five years: in 1938, the Germans abandoned daytime keys and began to change the initial position of the rotor before each message. The operator sent the initial key, followed by the encrypted key for the given message. Thus, two factors of the system's vulnerability were eliminated: universal day keys for all radiograms and encryption of the message key twice (this practice, of course, helped codebreakers find patterns between letters).

In response to a new challenge, Poland created the “Bomb” - six interconnected Enigma machines that could, in a couple of hours, use brute force to calculate the initial key of radio encryption (the starting position of the reels). The deciphering machine received its unusual name for the characteristic ticking sound during operation, reminiscent of the sound of a clock mechanism. In fact, it was the prototype of a computer, in which cardboard punched cards were used as information storage media. The occupation of Poland in 1939 and the next complication of the Enigma design forced France and Great Britain to look for new ways of “hacking.”

The private estate of Bletchley Park in Buckinghamshire became the nerve center of the British intelligence services during the Second World War. It was here in 1939 that the most talented mathematicians and cryptanalysts gathered with one goal - to crack the Enigma code. The priority objectives of the program, called "Ultra", were the encryption of the German fleet - the Kriegsmarine, whose submarines sank many ships and sent cargo worth millions of pounds sterling to the bottom.

Alan Turing - Cambridge professor who managed to crack the Enigma code

From the very beginning of the research center known as Station X at Bletchley Park, a young professor from Cambridge stood out among the codebreakers. Alan Turing. He led the group that built the Bomba supercomputer using a Polish analogue. The machine processed thousands of German codes that were intercepted by British radios. In this gigantic volume of information, general patterns of the work of Enigma gradually began to emerge - the German radio operators turned out to be not without sin. Greetings, careless encoding of numbers, frequently repeated snippets of text - all these deviations from the encryption protocol were strictly taken into account in Station X. Over time, about 200 Bomb-type decryptors were built, which made it possible to process 3,000 German ciphers per day. By 1942, the Ultra scientific team was able to make significant progress towards the goal, but there were regular failures: the constant complications of Enigma and changes in work algorithms had an effect.

Turing's "bomb" consisted of 108 electromagnetic drums and weighed 2.5 tons

The British anti-submarine ship, which captured the German submarine U-559, provided invaluable assistance to the scientists. She had on board a complete and unharmed copy of Enigma with a complete set of documentation and a set of ciphers. British Prime Minister Winston Churchill spoke exhaustively about the significance of the Enigma decryption program: “It was thanks to Ultra that we won the war.”

A very strange monument in front of the entrance to the Imperial Palace of Poznan - a monument to Polish cryptographers, decipherers of the Enigma code. The stela, in the form of an equilateral triangular prism, is 3.10 meters high and is covered with seemingly random sequences of numbers. On each side of the monument there are 21 lines of twelve numbers, without any visible meaning. In the center of each face are letters that form names.

The monument was unveiled here in 2007, on the 75th anniversary of the decipherment of Enigma by three Polish cryptanalysts Marian Rejewski (1905-1980), Jerzy Rozycki (1909-1942) and Henryk Zygalski (1908-1978). The opening ceremony took place on November 10, 2007 (all sources mention that the cipher was broken in December 1932, without specifying the exact date) in the presence of Rejewski's daughter, Rozycki's son, Mr. Jan Janusz Rozycki and two relatives of Henryk Zygalski. Other relatives of the three scientists, their former managers and colleagues from BS (Biuro Szyfrów) in Warsaw, PC Bruno and Cadix (the French branch of the bureau after the German occupation of 1939) were present.

The fact is that after the end of the First World War, part of the premises of the palace were given to the University of Poznan. In 1929, courses in cryptography, organized by the Polish Biuro Szyfrów (BS), began to operate in the rooms of the Faculty of Mathematics. Three students - Re(zh)evsky, Rozhitsky and Zygalsky were especially successful.

The Enigma code was invented by German cryptologist Arthur Scherbius in 1918, and began to be used in the Weimar Republic in the mid-1920s. At first experimentally, and since 1930 more and more often. Germany's neighbors, especially France, Britain and Poland, were suspicious, especially when the Nazis came to power in Germany in 1933. As part of the rearmament of the Wehrmacht, Scherbius encryption machines (by that time, as a result of a serious modification, it had turned from a 50-kilogram Model A into a Model C the size of a typewriter) began to be used for encryption in all branches of the military.

The French and British were unable to decipher the Enigma code (Greek Riddle), and called it “indestructible”. However, 27-year-old Rejewski, in his work in the BS4 division, cracked the code already in 1932. This was helped by a serious mistake made by Scherbius himself. If anyone is interested, you can read the article on Wiki (for me personally, a lot of things there provoke a reaction in the form of a facepalm)

Another article is about the British Museum, dedicated to this problem. Only there the Poles are not mentioned AT ALL, which in general is not surprising for the British.

In general, everything in this story is “beautiful”, starting from either the invention of Enigma by Scherbius himself, or the purchase of a patent from the Dutchman Hugo Koch, and ending with the “chemical castration” and suicide of the outstanding British scientist Alan Turing, who is known throughout the world, like an Enigma decoder.

But let's return to the Poles. When in the summer of 1939 it was already clear to everyone that Poland was about to fall, all the work of Polish scientists was transferred to British and French intelligence. There is no doubt (for me personally, yay) that this information was decisive for the work of British decryptors. The English mathematician and cryptanalyst Gordon Welchman, who was one of the leading employees of Bletchley Park (see the link about the British Museum), directly mentioned Polish contribution and assistance, writing: “... if they had not done this, the British cracking of Enigma might well not to happen at all...” It is believed that the deciphering of the Enigma code by British cryptographers shortened the war by about 2 years and saved many millions of lives.

Now there is a small museum next to the monument.

Here you can take short courses in cryptology :)

Unfortunately, we didn’t get to the museum because we were there after everything was closed, but I have Wikipedia!

Dmitry Alexandrovich was eager to see the monument with every fiber of his soul (before entering Pozan, I had no idea that it was there at all 0_0) and was completely satisfied, in principle, from here we could go back to our room *it seems*

But I’m glad that I found out this whole story (I knew about the Polish part, about Turing before, I should now watch the film with our Cumberbatch)

The development of the Enigma family of encryption machines started immediately after the First World War, back in 1918. The German Arthur Scherbius received a patent for a rotary encryption machine, which, in fact, was the first version of the “Riddle” (as Enigma is translated from German). In 1923, Scherbius, together with a partner, organized an enterprise with the difficult-to-pronounce name Chiffriermaschinen Aktiengesellschaft, which established the serial production of encryption devices.

The first two Enigma models, A and B, were moderately successful. The real breakthrough in 1925 was the Model C - with a reflector, much more compact than its predecessors. Enigma C weighed only 12 kg with dimensions of 28 by 34 by 15 cm, while previous models weighed about 50 kg, with dimensions of 65 by 45 by 35 centimeters. Model C almost immediately began to be used on ships of the German fleet.

Enigma S. Image: Crypto Museum

In 1928, military specialists commissioned by the Wehrmacht redesigned the design of civilian encryption machines, constructing the Enigma-G model, which two years later was modified into the Enigma-I version. It was this 1930 device that became the basis for many versions that were used by a variety of military services during World War II. There were Enigma variants with a number of rotors from 3 to 8. However, the eight-rotor version, created specifically for higher army structures, was quickly taken out of service due to unreliability.

"Drain" that did not turn into hacking

Although Enigma was praised by the highest ranks of the German army for its effectiveness and reliability, the secrecy of the messages encrypted on it was soon threatened. The reason for this was agent Asche - aka Hans-Tilo Schmidt, an employee of the encryption bureau of the German Ministry of Defense since 1931 - an agent of French intelligence. Schmidt handed over obsolete codes to the French, which he was obliged to destroy, and also “leaked” instructions for using a military version of the encryption machine.

Sheet with Enigma encryption codes. Photo: Telenet

French intelligence reacted rather coolly to the information of “agent Ashe”. Having your own agent in the camp of a potential enemy was useful, but Enigma was considered such a reliable machine that they didn’t even try to break it in France.. But in Poland, to which the French transferred materials from their German agent, there were cryptographic geniuses who figured out the code.

"Polish Turing"

The Reliable Machine was hacked by Marian Rejewski, a 27-year-old mathematician who completed secret courses in cryptography. Although he did not work alone in the Polish Cipher Bureau, only Rejewski was entrusted with working on decrypting Enigma I. Marian immediately began actively looking for vulnerabilities in the message key, selecting the first six letters from the daily ciphergrams and compiling correspondence tables.

First, he managed to discover 4 repeating sequences of letters in the ciphers. And then, thanks to the information that Enigma has only three reels, and the initial setting consists of three letters of the Latin alphabet, Rejewski established the number of possible code chains. It turned out to be many times smaller than previously expected: 3! 263 against 26!. This made it possible to compile a complete catalog of all chains within a year.

Thanks to Reevsky, it became clear that the number of code chains is 3,824,262,831,196,002,461,538 times less than previously assumed.

Marian Rejewski. Photo: Poland

Apparently, having realized that their ciphers could be read, German cryptographers began to change the configuration of the machine’s rotors much more often. And in the fall of 1938, the encryption principle was changed, which made it impossible to recognize ciphergrams based on previous methods. However, Reevsky and his colleagues saw through this trick, which consisted of the so-called key doubling and was, in fact, a cryptographic error.

Within a few months, the Poles created a device called the “Rejewski Bomb”, so named either for the characteristic ticking sound when working, or in honor of the round cakes that Marian loved very much. The device searched by pattern, taking into account that the pairs of the first and fourth, second and fifth, third and sixth letters of the cipher text corresponded to the same letters of the unciphered text.

Rejewski's cryptological "bomb". 1 - rotors for selecting keys, 2 - motor for rotating the rotors, 3 - indicator stand indicating successful selection of the code. Image: Ministerstwo Edukacji Narodowej

It was the work of Marian Rejewski that became the basis for Alan Turing's success. Although it cannot be said that the Briton merely appropriated someone else’s success. Yes, in 1939, during the attack of the Third Reich troops, the Poles transferred all the work of local codebreakers to British intelligence agents. But by this time Reevsky’s technique was useless for working with Enigma.

Chasing mistakes and trying options

Already in December 1938, two more rotors were added to the machine’s three rotors, and the number of possible rotor positions increased 10 times. Instead of 6 “Rejewski bombs”, the Poles even then needed 60 decryption devices. And in May 1940, the Germans abandoned the idea of ​​doubling the key, and the very concept of the Polish decryption machine turned out to be useless. So Turing did a huge amount of work to solve the improved “Riddle” - especially since Polish cryptanalysts destroyed the “bombs” in September 1939, after German troops invaded the country.

Rejewski was a genius, but he made a mistake by constantly looking for the mistakes of others. The Polish codebreaker's method was to identify Enigma vulnerabilities. But the Germans themselves constantly improved their machine, forcing the young mathematician to constantly be in a catching-up position.

The British were no longer suitable for the “Rejewski bomb”, which used an exhaustive search of all possible combinations to select a key.

Turing proposed a simpler and less labor-intensive method of decryption: take into account in your work that part of the source text is known. Despite the ingenuity of the German code, despite all the precautions, German soldiers most often communicated with each other in short, stereotypical phrases that could be “recognized.” The exact place of individual phrases in the encryption could be determined by mechanically enumerating 26 letters of the Latin alphabet. An additional relief was that in the Enigma cipher, none of the letters of the original message were encoded with the same letter.

"Bomb" for the Third Reich

Based on this technique, Turing Bombs were developed. The first was launched on March 18, 1940 - for each possible initial position of the rotors, it performed a comparison with a known fragment of text and formed logical assumptions. If inconsistencies were found in these assumptions, the option was “rejected.” Thus, from a huge variety of options - 10 19 possible combinations for the usual version of Enigma or 10 22 for the version used by submariners - only a few logically consistent ones remained, on the basis of which the machine selected the cipher. The team of decryptors worked around the clock, in several shifts a luxurious mansion called Bletchley Park in the town of Milton Keynes, 72 km from London. Employees processed thousands of messages daily, highlighting so-called clues in the ciphergrams - greetings, numbers, repeating pieces of text. Based on these fragments, the machine made its assumptions.

Sometimes it happened that the information was not enough to solve the code. This was especially critical on the eve of major German operations. Back then, British troops resorted to a technique called gardening. To do this, the British Navy carried out demonstrative mining of certain areas of the sea, and in Bletchley Park they then determined a known text based on enemy reports on mine clearance.

A genius appreciated too late

Turing did everything to ensure that England did not surrender under the onslaught of the German fleet and aviation, and the USSR had not only America as its allies. As one of Alan’s colleagues once said: “I don’t presume to say that we won the war thanks to Turing. However, without him they could have lost it.”

Alan Turing is considered one of the most important figures in the history of cryptography. But his work on deciphering Enigma hardly influenced the development of this science - no matter how strange it may sound. All decryption machines from Bletchley Park were destroyed after World War II, and the very fact of decryption attempts - successful and not so successful - was kept secret until the 1970s. Already in 1952, the scientist himself turned from an unknown hero into an object of public shame: Turing was accused of homosexuality and forced to undergo a course of hormonal therapy, from which the “Enigma winner” fell into deep depression and committed suicide two years later.

In 2009, Alan Turing was recognized as "one of the UK's most famous victims of homophobia". In 2013, Britain's Queen Elizabeth II formally pardoned Turing, who was accused of "obscenity."

And yet: today the name Turing is familiar to most people. The Turing Completeness Principle, the Turing Test, the Turing Machine, and one of the most prestigious awards in computer science are named after the genius. In the movies, Alan was played by the terribly fashionable Benedict Cumberbatch, and a monument to him was erected in Manchester.

But the German Navy was the first to use Enigma. It was a 1925 Funkschlüssel C model. In 1934, the Navy adopted a naval modification of the army vehicle (Funkschlüssel M or M3). At that time, the army used only 3 rotors, and in the M3, for greater safety, you could choose 3 rotors out of 5. In 1938, 2 more rotors were added to the kit, in 1939, 1 more, so it became possible to choose 3 out of 8 rotors. And in February 1942, the German submarine fleet was equipped with a 4-rotor M4. Portability was preserved: the reflector and the 4th rotor were thinner than usual. Among the mass-produced Enigmas, the M4 was the most secure. It had a printer (Schreibmax) in the form of a remote panel in the commander's cabin, and the signalman worked with encrypted text, without access to classified data. But there was also special, special equipment. The Abwehr (military intelligence) used a 4-rotor Enigma G. The level of encryption was so high that other German authorities could not read it. For the sake of portability (27x25x16 cm), the Abwehr abandoned the patch panel. As a result, the British managed to hack the machine's security, which greatly complicated the work of German agents in Britain. “Enigma T” (“Tirpitz machine”) was created specifically for communication with its ally Japan. With 8 rotors, reliability was very high, but the machine was hardly used. Based on the M4, they developed the M5 model with a set of 12 rotors (4 working/8 replaceable). And the M10 had a printer for open/closed texts. Both machines had another innovation - a gap-filling rotor, which greatly increased the strength of the encryption. The Army and Air Force encrypted messages in groups of 5 characters, the Navy - in groups of 4 characters. To make it more difficult to decrypt enemy interceptions, the texts contained no more than 250 characters; long ones were broken into parts and encrypted with different keys. To increase security, the text was clogged with “garbage” (“letter salad”). It was planned to re-equip all types of troops with M5 and M10 in the summer of 1945, but time ran out.

So, the neighbors were “blind” to Germany’s military preparations. The Germans' radio communication activity increased many times over, and it became impossible to decipher the interceptions. The Poles were the first to be alarmed. While keeping an eye on their dangerous neighbor, in February 1926, they suddenly could not read the encryption of the German Navy, and from July 1928, the encryption of the Reichswehr. It became clear: they switched to machine encryption. In January 29th, Warsaw customs found a “lost” parcel. Berlin's harsh request to return it attracted attention to the box. There was a commercial Enigma. Only after studying it was given to the Germans, but this did not help reveal their tricks, and they already had a reinforced version of the machine. Especially to combat Enigma, Polish military intelligence created the Cipher Bureau of the best mathematicians who spoke fluent German. They were lucky only after 4 years of marking time. Luck came in the form of an officer of the German Ministry of Defense, “bought” in 1931 by the French. Hans-Thilo Schmidt (“Agent Asche”), responsible for the destruction of outdated codes of the then 3-rotor Enigma, sold them to the French. I also got them instructions for it. The bankrupt aristocrat needed money and was offended by his homeland, which did not appreciate his services in the First World War. French and British intelligence showed no interest in this data and handed it over to their Polish allies. In 1932, the talented mathematician Marian Rejewski and his team cracked the miracle machine: “Ashe’s documents became manna from heaven: all the doors instantly opened.” France supplied the Poles with agent information until the war, and they managed to create an Enigma simulator, calling it a “bomb” (a type of ice cream popular in Poland). Its core was 6 Enigmas connected into a network, capable of sorting through all 17,576 positions of the three rotors, i.e., all possible key options, in 2 hours. Her strength was enough to open the keys of the Reichswehr and the Air Force, but she could not split the keys of the Navy. The “bombs” were made by the company AVA Wytwurnia Radiotechniczna (it was the company that reproduced the German “Enigma” in 1933 - 70 pieces!). 37 days before the start of World War II, the Poles passed on their knowledge to the allies, giving them one “bomb” each. The French, crushed by the Wehrmacht, lost their car, but the British turned theirs into a more advanced cyclometer machine, which became the main instrument of the Ultra program. This counter-Enigma program was Britain's best-kept secret. The messages decrypted here were classified as Ultra, which is higher than Top secret. Bletchley Park: Station X: After the First World War, the British cut their cryptologists. The war with the Nazis began - and all forces had to be urgently mobilized. In August 1939, a group of code-breaking specialists entered the Bletchley Park estate, 50 miles from London, under the guise of a company of hunters. Here, at the decryption center Station X, which was under the personal control of Churchill, all information from radio interception stations in Great Britain and abroad converged. The company "British Tabulating Machines" built here the first decoding machine "Turing bomb" (this was the main British cracker), the core of which was 108 electromagnetic drums. She tried all the options for the cipher key given the known structure of the message being deciphered or part of the plaintext. Each drum, rotating at a speed of 120 revolutions per minute, tested 26 letter options in one full revolution. During operation, the machine (3.0 x2.1 x0.61 m, weight 1 t) ticked like a clockwork, which confirmed its name. For the first time in history, ciphers created en masse by a machine were also solved by the machine.

To work, it was necessary to know the physical principles of the Enigma down to the smallest detail, and the Germans constantly changed it. The British command set the task: to obtain new copies of the machine at all costs. A targeted hunt began. First, they took a Luftwaffe Enigma with a set of keys from a Junkers shot down in Norway. The Wehrmacht, smashing France, advanced so quickly that one signal company overtook its own and was captured. The Enigma collection was replenished by the army. They were dealt with quickly: Wehrmacht and Luftwaffe encryption began to appear on the table of the British headquarters almost simultaneously with the German one. The most complex one was desperately needed - the naval M3. Why? The main front for the British was the sea front. Hitler tried to strangle them with a blockade, cutting off the supply of food, raw materials, fuel, equipment, and ammunition to the island country. Its weapon was the Reich's submarine fleet. The group tactics of the “wolf packs” terrified the Anglo-Saxons, their losses were enormous. They knew about the existence of the M3: 2 rotors were captured on the submarine U-33, and instructions for it on the U-13. During a commando raid on the Lofoten Islands (Norway) on board the German patrol ship "Crab" they captured 2 rotors from the M3 and keys for February, the Germans managed to drown the car. Moreover, it turned out quite by accident that there were German non-military ships sailing in the Atlantic, which had special communications on board. Thus, the Royal Navy destroyer Griffin inspected the allegedly Dutch fishing vessel Polaris off the coast of Norway. The crew, consisting of strong guys, managed to throw two bags overboard, and the British caught one of them. There were documents for the encryption device. In addition, during the war, the international exchange of weather data ceased - and converted “fishermen” went from the Reich to the ocean. On board they had Enigma and settings for every day for 2-3 months, depending on the duration of the voyage. They regularly reported the weather and were easy to find. Special Royal Navy task forces came out to intercept the “meteorologists.” Fast destroyers literally took the enemy to task. By shooting, they tried not to sink the “German”, but to drive his crew into panic and prevent the destruction of special equipment. On May 7, 1941, the trawler Munich was intercepted, but the radio operator managed to throw the Enigma and May keys overboard. But in the captain’s safe they found the keys for June, a short-range communication code book, a coded weather log and a Navy coordinate grid.  The mining helped: the time from intercepting a message to decrypting it was reduced from 11 days to 4 hours! But the keys had expired and new ones were needed. Captain Lempt's mistake Surrender of the German submarine U-110 to the British. May 9, 1941 The main catch was made on May 8, 1941 during the capture of the submarine U-110 of Lieutenant Commander Julius Lemp, which was attacking convoy OV-318. After bombing U-110, the escort vessels forced her to surface. The captain of the destroyer HMS Bulldog went to ram, but, seeing that the Germans were jumping overboard in panic, he turned away in time. Having penetrated the half-submerged boat, the boarding party discovered that the team had not even tried to destroy the secret communications means. At this time, another ship picked up the surviving Germans from the water and locked them in the hold to hide what was happening. This was very important. U-110 took: a working Enigma M3, a set of rotors, keys for April-June, encryption instructions, radiograms, logs (personnel, navigation, signal, radio communications), sea charts, diagrams of minefields in the North Sea and off the coast France, operating instructions for type IXB boats.    d. Sea convoys began to bypass the “wolf packs”: from June to August, the “Doenitz wolves” found only 4% of convoys in the Atlantic, from September to December - 18%. But the Germans, believing that U-110 had taken its secret into the abyss, did not change the communication system. Admiral Doenitz: “Lemp did his duty and died as a hero.” However, after the publication of Roskill’s book “The Secret Capture” in 1959, the hero became, in the eyes of German veterans, a scoundrel who had tarnished his honor: “He did not carry out the order to destroy secret materials! Hundreds of our boats were sunk, thousands of submariners died in vain,” “if he had not died at the hands of the British, we should have shot him.” And in February 1942, the 4-rotor M4 replaced the 3-rotor M3 on boats. Bletchley Park has hit a wall again. All that remained was to hope for the capture of a new vehicle, which happened on October 30, 1942. On this day, Captain-Lieutenant Heidtmann's U-559 northeast of Port Said was heavily damaged by British depth charges. Seeing that the boat was sinking, the crew jumped overboard without destroying the encryption equipment. She was found by sailors from the destroyer Petard. As soon as they handed over the loot to the boarding party that arrived in time, the mangled boat suddenly capsized, and two daredevils (Colin Grazier, Antony Fasson) went with it to a kilometer depth. The spoils were the M4 and the "Brief Call Sign Log"/"Brief Weather Code" brochures, printed with soluble ink on pink blotting paper, which the radio operator was supposed to throw into the water at the first sign of danger. It was with their help that on December 13, 1942, the codes were opened, which immediately gave the headquarters accurate data on the positions of 12 German boats. After a 9-month break (black-out), the reading of ciphergrams began again, which did not stop until the end of the war. From now on, the destruction of the “wolf packs” in the Atlantic was only a matter of time. Immediately after rising from the water, German submariners were completely undressed and all their clothes were taken away in order to search for documents of interest to intelligence (for example, code tables of the Enigma cipher machine). A whole technology for such operations has been developed. Bombs were used to force the boat to the surface and they began shelling with machine guns so that the Germans, remaining on board, would not begin to sink. Meanwhile, a boarding party was approaching her, aiming to look for “something like a typewriter next to the radio station,” “disks with a diameter of 6 inches,” any magazines, books, papers. It was necessary to act quickly, and this was not always possible. Often people died without obtaining anything new. In total, the British captured 170 Enigmas, incl.   parts 3–4 sea M4. This made it possible to speed up the decryption process. When 60 “bombs” were turned on simultaneously (i.e., 60 sets of 108 reels), the search for a solution was reduced from 6 hours to 6 minutes. This already made it possible to quickly respond to uncovered information. At the peak of the war, 211 “bombs” operated around the clock, reading up to 3 thousand German encryption messages daily. They were served in shifts by 1,675 female operators and 265 mechanics. When Station X could no longer cope with the huge flow of radio interceptions, some of the work was moved to the United States. By the spring of 1944, 96 “Turing bombs” were working there, and a whole decryption factory had arisen. In the American model, with its 2000 rpm, the decoding was 15 times faster. Confrontation with the M4 has become a chore. Actually, this was the end of the fight with Enigma.

"Enigma" (from the Greek αἴνιγμα - riddle) is a portable encryption machine. Initially, it was used for commercial purposes to maintain the secrecy of business correspondence; during World War II, the device was used by the German command.

Enigma encryption machine. Photo: www.globallookpress.com

How did Enigma encrypt the code?

The device consisted of a keyboard and a set of rotating disks - rotors. During the encryption process, the device changed some letters to others, for example, instead of the letter “A”, “T” was used, instead of “B” - “S”, etc. The code could be read by someone who knew the “key” to it. In essence, Enigma was a dynamic Caesar cipher.

When coding, the Germans used only 26 letters and sent messages in groups of five characters. Long messages were broken into parts, each of which used its own “key”.

Who invented Enigma?

Invented this encryption machine in 1915 American Edward Hepburn. The device was subsequently used throughout the world and was greatly improved by cryptographers of the Third Reich.

How difficult was it decipher the code"Enigma"?

The Third Reich believed that Enigma could not be cracked because it had 2x10 to the 145th power of encoding options.

Who was able to decipher the Enigma code?

The Enigma code was deciphered in 1939. British mathematician Alan Turing, which allowed official London to know in advance about the plans of the Third Reich. In 2014, the film “The Imitation Game” was released in Russia, which is dedicated to this episode in history.

* Caesar cipher is a type of substitution cipher in which each character is replaced by a character located at a certain constant number of positions to the left or right of it in the alphabet. For example, in a cipher with a right shift of 3, the letter A would become D, B would become D, and so on. The cipher is named after Roman Emperor Gaius Julius Caesar, who used it for secret correspondence with his military commanders.