Topic of extracurricular activities: The history of one code.

Lesson type: discovery of new knowledge

ICT tools used in the lesson:

Teacher's personal computer (PC), multimedia projector, screen;

Students' PC, handout.

Characteristic learning opportunities groups:

Students are fluent in:

subject:

ways of encoding information, they know how to work with the Caesar cipher (from the elementary school course).

metasubject:

educational: -

able to structure the acquired knowledge

regulatory :

plan activities in the classroom;

capable of self-assessment of performance.

communicative:

able to express their thoughts with sufficient completeness and accuracy.

personal:

are able to build communicative relations in a group of like-minded people, are capable of reflection.

possess the skills of teaching and research activities.

Target:

conduct a study of the history of the creation of the Caesar cipher and present the results in the form of a mental map.

Tasks:

teach how to work with a mental map

teach information search;

learn to extract the necessary information;

to form communicative competencies;

During the lesson, the teacher creates such conditions under which children will have the opportunity to:

feel like a part of a team united by work in the network project “In the World of Codes”;

learn how to work safely on the Internet;

learn to work in the service;

learn to structure the information received.

Planned educational outcomes :

subject:

development of skills to work with the educational text, to highlight the main thing:

1) the name of the cipher is presented;

3) the battle is indicated, the year, who fought the war and with whom;

4) there is an illustration of this cipher;

5) the key to unraveling the cipher is presented.

formation of skills and abilities to work safely with computer programs and on the Internet;

1) the map access settings are correctly specified (available to everyone on the Internet without editing rights)

formation of the ability to comply with the norms of information ethics and law

metasubject:

cognitive -

formulation of the cognitive goal;

search for the necessary information in the open information space;

capture information using ICT.

regulatory -

planning activities in the lesson;

mutual evaluation of work results.

communicative -

the ability to organize educational cooperation (distribution of responsibilities of participants);

the ability to argue and defend one's opinion.

personal:

punctuality in work (tasks were carried out strictly on time);

manifestation of independence in the search for information;

manifestation of independencein creating a mental map.

Basic concepts studied in the lesson:

Code, cipher, alphabet, key.

Brief annotation of the extracurricular activity “History of one code”

Main character project “In the World of Codes”, within which the lesson takes place, the cat Codfield invites scientists of cryptographers to help him in studying the history of the emergence of ciphers. For the duration of the lesson, students become cryptographic scientists helping the cat Codfield to study the history of the emergence of the Caesar cipher. As part of the lesson, students explore materials on the topic of the history of information coding, learn to use the safe Internet and structure the information received using the mental map creation service. Work in the classroom requires students to draw up an algorithm of actions, make decisions in the course of working with a map, and be able to evaluate the action of a friend according to specified criteria.

During the lesson, students can refer to the presentation to work with links on their own. The presentation was created in Google, which allows the teacher to allow a certain circle of students to work with it, giving them access to editors.

During the lesson, the slides are shown in the following sequence.

slide 1. Lesson topic.

Slide 2. Watching the cartoon “Fairy tale machines - Ali Baba. After viewing, the meaning of the word code is found out.

Slide 3. With the help of a teacher, students find out who a cryptographer is, what he does, what qualities he possesses. The teacher invites students to tell what qualities they already have and what else they need to learn.

slide 4. Goal setting. Formulation of the problem. .

Slide 5. The students make a plan of action. On the slide, the student action plan is not in order. Students independently form an algorithm of activity and voice it. By clicking on the screen, the correct work plan appears. The students formulate the goal of the lesson.

slide 6. After discussing the rules of the road, it turns out who invented them. On the slide is an image of Caesar and brief information about him. There is a discussion about what Julius Caesar became famous for, the teacher finds out what the students know about encryption, its purpose.

Slide 7 . Introduction to the service. The teacher explains the rules for working with the service. Through the link in the title of the slide, there is a transition to the training page on the site nachalka.com.

slide8 . The teacher demonstrates a mental map template, according to which students create their own map, give access to other participants.

slide 9. Using the link in the presentation, students go to the children's search engine to conduct research and find answers to the questions asked.

slide 10. Dynamic pause “Gymnastics for the eyes”

slide 11 . Map work. Students create a map according to the template, fill in the fields of the map with the collected information. Post links to created maps.

slide 12. Using the links to the form “Peer-assessment sheet "Working with a mental map", students go to the Google form, with which they evaluate the work of their comrades. Return to slide No. 10, follow the links to the maps and evaluate each other's work.

slide 13. Reflection of students' activities is carried out. The slide contains questions that will help students figure out what they experienced difficulty in completing tasks and what they coped with easily. It turns out what qualities they acquired during their work and whether they approached the image of a scientist cryptographer.

slide 14. Links to tables with student and teacher grades are provided. By clicking on the links, students will see the final grades for their work. The final grade is the sum of the grades of the students and the teacher. The work with the most points is posted on the website of the project “In the World of Codes”

slide 15. Words of gratitude.

Slide 16. List of useful sites, used when finding information is difficult.

slide 17. Links to electronic resources. Not shown.

Lesson progress:

Motivational-target stage

Organizing time

Teacher:

Hello guys! Today we will start our lesson by watching a cartoon about Masha, where she composes a fairy tale about Ali - Baba.

Video is being shown “

Guys, what did Ali Baba know, what allowed him to enter the cave, and what did the greedy brother not know to get out of the cave?

Students:

Forgot Magic word.

Teacher:

What is another name for the magic word? This term is familiar to you, it is present in the title of our lesson.

Students:

He forgot the code

Teacher:

Tell me what is the code?

Students:

encrypted word.

Teacher:

A code is a separate combination of symbols (characters).Guys, for the second lesson we are participating in the project “In the World of Codes”, at the first lesson we met the cat Codfield, who invited us to fascinating world codes. Today he invites us into the world of history and gathers a group of cryptographers studying the history of the emergence of the Caesar cipher. In the creative group, he needs young (this is about us), creative (this is also about us), but at the same time, girls and boys who are ICT-competent and deeply knowledgeable in coding information. Guys, how do you imagine him as a young scientist cryptographer? What does he study, what science? What qualities should he have?

Students:

Cryptographer - scientist studying information encryption methods. He must be smart, interested in the subject, researcher, observant, sociable, sociable, loving his job, persistent, not afraid of difficulties.

Teacher:

Surely this scientist knows a lot about encoding information and knows how to use any services on the Internet.

Which of these qualities do you already possess?

Students:

We are inquisitive, we know how to use a computer, we like to learn new things and explore new services, we love to work on the Internet.

Teacher:

Then this is the journey for us.

Goal setting. Guys, let's try to determine the purpose of our lesson.

Codfield has given us a difficult task. He asked the guys from different schools to unite in search of information about the history of the creation of ciphers and codes. And the received data will be processed and placed in the mind map, which we will make with you using the SpiderScribe.net service.

Best works Codfield will post on the website of the project “In the World of Codes”.

What do you know about the Caesar cipher?

Pupils: (if the students do not know the answer, the teacher completes)

It was created by the ancient Roman general Gaius Julius Caesar.

Each character in the text is replaced by a character that is some constant number of positions to the left or right of it in the alphabet.

Teacher:

Well, well done, you received this knowledge in elementary school.

Problem: Is it possible, knowing the material halfway, to seriously address the problem? What do you need to know for this? Try to plan the activities in the correct order: they are presented on the slide. Arrange them in the correct order.

Students:

find information on a given topic,

highlight the main

answer the questions asked

learn to work with a mental map,

place the received information in a mental map.

The purpose of our lesson explore the history of the creation of the Caesar cipher, present information in a mental map.

Knowledge update

Teacher:

You know that in ordinary life we ​​are surrounded by information encoded in signs, symbols, sounds and most of these codes we can decipher and understand their meaning. For example, road signs. What are they talking about?

Students:

They talk about the rules of the road. How to behave on the road so as not to get into an accident.

Teacher:

Do you know who was the first to introduce the rules of the road?

Students:

No

Yes, Caesar.

Teacher:

Gaius Julius Caesar - the first Roman general who introduced the rules of the road. But he became famous as an outstanding commander who won more than one battle. And for correspondence with his generals, he came up with a cipher that began to bear his name - the Caesar cipher.

Introduction to new material

Teacher:

The cipher helped to hide information from prying eyes. And who could read the messages?

Students:

The one who had the key to the cipher.

Teacher:

That's right, a cipher has no meaning if there is no key to it. Information in the encryption process goes through two stages: the first is the encoding process, when we apply the encoding alphabet to the text, the second is decoding, when we apply the cipher key to the encrypted information in order to find out the true meaning of the message.

Today we will learn the history of the creation of the Caesar cipher, and I will not tell it, tell and show the history of the cipher using the service

service for creating mental maps. This is a new program for you in which you will learn how to work and present information.

A mental map is a map of the mind that represents information visually. It helps you present information in a diagram.

Before we start searching for the information we are interested in, we will get acquainted with the program and create a mental map.

teacher's word

Using the tutorial on nachalka.com. the teacher explains the rules for working with the service.

Setting up map access

Demonstrates as a model for students to create a map.

After the teacher introduced the students to the rules of work in the service and gave a template for filling out the card, the students begin to complete the task.

Student actions according to the algorithm

launch google chrome

enter the name of the service in the search bar

register in the service to receive three free cards

Dynamic pause. Gymnastics for the eyes.

Practical stage:

Task for students: creating a mental map “History of one code”

Finding answers to questions

1) Find answers to questions. For information, use the children's search engine at nachalka.com.

The name of the cipher (code).

Who created and in what year?

Alphabet (image of cipher alphabet)

The key to unraveling the cipher (image).

In what battle was the cipher used?

Group work

Distribution of duties by students

After the children have found the necessary information, they are divided into groups for joint work with a mental map. (group of 3 people)

Distribution of roles

Students are encouraged to draw up a group action plan and distribute responsibilities among themselves.

When the group is divided, responsibilities are distributed:

1) 1 student gives other participants access to the map;

2) participants distribute among themselves fields for filling

Working with the map

1) Draw up a mental map according to the sample.

2) Fill in the fields of the card with information.

3) Conclude by answering the question: How does encryption help win the war? (Write in your own words 1.2 sentences).

Reflective - evaluative stage

Teacher:

Guys, you have created a mental map “History of one code”. Did you like it? What was the most difficult part of the assignment? What did you like most about your work? Do you think you managed to get closer to the image of a scientist - a cryptographer? What qualities do you now possess, what have you learned?

Students:

We tried to be explorers, were observant when we found the right information, discussed our responsibilities, were persistent in creating a mental map.

Teacher:

Well done, you coped with the tasks of the lesson, It was more difficult to do it alone. I suggest that you evaluate the work of your comrades using the Google form. By clicking on the links on slide No. 12 “Mutual evaluation”.

I appreciated your work and also put points for the task. The teacher evaluates the work of students using the form

Annex 1.

Working with a mental map.

Access settings.

Appendix 2

Mind map template “History of one code”

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

Birth of a legend

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

Paradoxically, the Enigma cipher machine was not created for the military, but for secrecy business negotiations. The device was developed and patented in 1918 by a German engineer Arthur Sherbius."Enigma" of the first series weighed more than 50 kg. Due to the high cost and difficulty in use, the cipher machine did not attract the attention of buyers at first. 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 cipher machine, which means "mystery" in Greek. In 1908 he graduated from the University of Hannover, and ten years later he organized the private firm Scherbius and Ritter, which was engaged in the production of Enigma. The inventor did not live to see the triumph of his offspring - he died in 1929 as a result of an accident.

The cipher machine was 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 scramblers produced before and during World War II exceeded 100,000. They were used by all types of the armed forces of Nazi Germany, as well as military intelligence and security services.

Enigma ciphers

The operator encrypted the message according to the code book. The entries looked like this:

We see installations on the 31st day of the month (the code changed every day). The operator must select the reflector B, put on the rotors IV, I, VII the letters C, T and R, respectively. Next comes the order of closing the contacts on the cross-panel. When encrypting, the operators followed the general rules: spaces are not put, punctuation marks are indicated by symbols (for example, a comma is YY, and quotation marks are X). In addition to the daily 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 (discs) with 26 electrical contacts on each - according to the number of letters of the Latin alphabet. With these contacts, the drums were in 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 the text on the keyboard. Each disk was responsible for an elementary encryption step - replacing one letter with another, for example, P with W. Three disks complicated the encryption logic many times over. Each keystroke caused an electrical impulse, which, passing through the drums, turned the first disk one step. After the first drum made a complete revolution, the second one came into action, then the third - it was like the work of an electric meter.

The electrical signal, passing through the drums, entered the reflector of the cipher 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 greatly complicated the encryption mechanics. Next, an electrical impulse lit one of the indicator lights, which showed the letter of the encrypted text.

Encryption device M-94

Three people usually worked on the first versions of Enigma 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. In the future, this became one of the most important clues that led to the breaking of the cipher.

How is Enigma arranged?

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

Reflector had 26 contacts and connected to the third rotor. He "reflected" the current from the third rotor and sent it back, but in a different way. The reflector guaranteed 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 in the encryption process.

Switch. Under the Enigma switch 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, a comma - YY). The numbers were written in words.

Cross panel. It was present in the military models of Enigma and was a set of sockets for plugs. It served to swap the contacts of two letters, the plugs of which 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 and preparing for war. Special attention was given deep secrecy in the transmission of information over radio channels. Therefore, all Enigmas worked under conditions of secrecy: for each session of the cipher machine, there were daily keys (a set of letters indicating the initial position of the rotors), which were the same 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 daily key is AOH. The operator and the recipient put up 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 double entry of the EINEIN key, 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 deciphered 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 drums. This significantly increased the resistance of ciphers to cracking. For some time, the highest command staff used the Enigma II, 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 fragments of phrases on the air. It can be said that the German signalmen used the spam attack for the first time. All these measures, undoubtedly, complicated the work of the secret services of Europe in deciphering the codes of the Third Reich.

"Wolf Packs" Dönitz

The ruthless submarine war waged by fascist Germany left few chances for merchant and military ships of the USSR, Great Britain and the USA. The main means of communication for the Kriegsmarine submarines was the naval version of the Enigma. With its help, the leadership organized strike groups of submarines and directed them to convoys in order to destroy them. Such a “wolf pack” attacked ships exclusively in a group and pursued tens of miles, launching several ships to the bottom. One of the inspirers of this tactic was the commander of the German submarine fleet, Karl Dönitz. With the decoding 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. In the late 1920s, a Polish group of cryptanalysts got their hands on a commercial version of Enigma. This made it possible to obtain general idea about the logic of the encryption machine. A few years later, French intelligence was able to get a 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 decrypt messages.

The art of cryptanalysis

The classic decoding technique is frequency analysis. The idea is that the frequency of occurrence of a certain letter and even a syllable in a long text is the same in any language and cipher. This makes it quite easy to decipher the codes created by replacing letters in the text - it is enough to carry out a reverse substitution. Rotary cipher machines such as Enigma were much more resistant to crypto-breaking, as they reduced the number of repeating sequences, which made frequency analysis powerless. Now cryptanalysis is based on the gigantic computing power of computers and is widely used by private corporations, intelligence agencies and hackers.

The most successful at this stage were the Polish cryptanalysts. Having gained access to the entire array of European intelligence data, they were able to read German encryptions from 1933. This lasted for five years: in 1938, the Germans abandoned day 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 the decoders to find patterns between letters).

In response to a new challenge, Poland created the "Bomb" - six interconnected Enigma machines, which could calculate the initial radio encryption key (the starting position of the drums) in a couple of hours by brute force. The decryptor machine received an unusual name for the characteristic ticking during operation, reminiscent of the sound of a clockwork. In fact, it was a prototype of a computer, in which cardboard punched cards were used as an information carrier. The occupation of Poland in 1939 and the increasing complexity of the Enigma design forced France and Britain to look for new ways to "hack".

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

Alan Turing, Cambridge professor who cracked the Enigma code

From the very beginning of the research center at Bletchley Park, known as Station X, a young professor from Cambridge stood out among the codebreakers. Alan Turing. He led a group that built the Bomba supercomputer based on the Polish counterpart. The machine processed thousands of German ciphers, which were intercepted by British radios. In this gigantic amount of information, the general patterns of the work of the Enigma gradually began to emerge - the German radio operators turned out to be not without sin. Greetings, careless coding 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 decoders were built, which made it possible to process 3000 German encryptions per day. By 1942, the scientific team of Ultra was able to seriously advance towards the goal, but there were regular failures: the constant complication of Enigma and changes in work algorithms affected.

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 scientists. She had on board a whole and unharmed copy of the Enigma with complete set documentation and cipher suite. British Prime Minister Winston Churchill said exhaustively about the significance of the Enigma decryption program: “It was thanks to Ultra that we won the war.”

All specialists unanimously agreed that a reading is impossible.
Admiral Kurt Fricke, Chief of Naval War Command

The Enigma is a rotary cipher machine used by Nazi Germany during World War II. Thanks to the impact it had on the course of the war, the Enigma hack was arguably the highlight of the centuries-long history of cryptanalysis. In this topic, I would like to talk about the hacking method used in Bletchley Park, as well as describe the device of the machine itself.

rotary machines

For the first time encryption rotary machines began to be used at the beginning of the 20th century. The main component of such devices is a disk (aka rotor) with 26 electrical contacts on both sides of the disk. Each contact corresponded to a letter English alphabet. Connecting the contacts of the left and right sides implemented a simple substitution cipher. As the disk rotated, the contacts shifted, thereby changing the substitution for each letter. One disk provided 26 different substitutions. This means that when encrypting the same character, the resulting sequence begins to repeat after 26 steps.
To increase the sequence period, several rotors connected in series can be used. When one of the disks makes a complete revolution, the next disk moves one position. This increases the sequence length to 26n, where n is the number of rotors connected in series.
As an example, consider the following image of a simplified rotary machine:

The given machine consists of a keyboard (for entering a character), three disks, an indicator (for displaying cryptotext) and implements encryption of 4 characters: A, B, C, D. In the initial position, the first disk implements substitution: A-C; B-A; C-B; D-D. The permutations of the second and third discs are A-B; B-C; C-A; D-D and A-A; B-C; C-B; D-D respectively.
When the letter B is pressed on the keyboard, an electrical circuit is closed, depending on the current position of the rotors, and a light on the indicator lights up. In the example above, the letter B will be encrypted in C. After that, the first rotor will move one position and the machine settings will look like this:

Enigma

Enigma is the most popular representative of the world of cipher rotary machines. It was used by the German troops during World War II and was considered virtually unbreakable.
The Enigma encryption procedure is implemented as in the above example, except for some additional touches.
Firstly, the number of rotors in different versions of Enigma could be different. The most common was the three-rotor Enigma, but a four-disk variant was also used.
Secondly, the decryption process of the demonstration rotary machine described above is different from the encryption process. Each time, for decoding, you will have to change the left and right rotor in places, which may not be very convenient. To solve this problem, another disk was added to Enigma, which was called the reflector. In the reflector, all contacts were connected in pairs, thus realizing the repeated passage of the signal through the rotors, but along a different route. Unlike the other rotors, the reflector was always in a fixed position and did not rotate.

Let's add a reflector that implements the substitution (A-B; C-D) to our demo cipher machine. When you press the B key, the signal passes through the rotors and enters the reflector through contact C. Here the signal is "reflected" and returned back, passing through the rotors in reverse order and along a different path. As a result, the letter B at the output is converted to D.
Note that if you press the D key, the signal will follow the same circuit, converting D to B. Thus, the presence of a reflector made the encryption and decryption processes identical.
Another property of Enigma associated with the reflector is the impossibility of encrypting any letter into itself. This property played a very important role in breaking the Enigma.

The resulting device is already very similar to the real Enigma. With one minor caveat. The stability of such a machine rests on the secrecy of the internal switching of the rotors. If the device of the rotors is revealed, then hacking is reduced to the selection of their initial positions.
Since each rotor can be in one of 26 positions, for three rotors we get 26 3 =17476 options. At the same time, the rotors themselves can also be arranged in any order, which increases the complexity by 3! once. Those. the key space of such a machine will be 6*17576=105456. This is clearly not enough to provide a high level of security. Therefore, Enigma was equipped with another additional tool: patch panel. By connecting letters in pairs on the patch panel, one could add another additional step to encryption.


For example, let's say that on the patch panel, the letter B is connected to the letter A. Now when you press A, the A-B substitution occurs first, and the letter B is fed into the input of the first rotor.
The message is decrypted in the same way. When the D key is pressed, the rotors and reflector produce transformation D-D-D-D-C-B-A-B. The plugboard then converts B to A.

Enigma Persistence Analysis

The real Enigma differed from the one described by the demonstration machine in only one way. Namely, in the device of the rotors. In our example, the rotor changes its position only when the previous disk completes a complete revolution. In real Enigma, each disk had a special notch that, at a certain position, picked up the next rotor and shifted it one position.
The location of the notch for each of the rotors could be adjusted using special outer rings. The initial position of the rings did not affect the switching of the rotors and the result of encryption of a single letter, so the rings are not taken into account when calculating the Enigma key space.
So, base model Enigma had 3 different rotors, numbered with Roman numerals I, II, III and implementing the following substitutions:
Entry = ABCDEFGHIJKLMNOPQRSTUVWXYZ
I = EKMFLGDQVZNTOWYHXUSPAIBRCJ
II = AJDKSIRUXBLHWTMCQGZNPYFVOE
III = BDFHJLCPRTXVZNYEIWGAKMUSQO
In encryption, the rotors could be arranged in any sequence, which for three rotors gives 6 different combinations.
In addition, each rotor could be installed in one of 26 possible starting positions. Those. the initial position of the rotors has only
6*26 3 =105456 combinations.
The number of all possible connections on the patch panel is calculated by the formula n! /((n-2m)! m! 2 m), where n is the number of letters of the alphabet, m is the number of connected pairs.
For 26 letters of the English alphabet and 10 pairs, this is 150738274937250=2 47 different combinations.
Thus, the basic version of Enigma with three rotors had a solid keyspace even by modern standards:
150738274937250*105456=15,896,255,521,782,636,000≈2 64 .
Such a huge number of options inspired a deceptive sense of invulnerability.

Enigma cryptanalysis

A large key space provides the Enigma cipher with a fairly serious level of resistance to attacks against a known ciphertext.
A complete enumeration of 2 64 options, even on modern computers, is not an easy task.
However, everything changes if you apply an attack with a known plaintext. For such a case, there is a very ingenious method that allows you to neglect the settings of the plugboard in the process of searching for a key combination, which reduces the Enigma key space to only 105456 combinations and makes the entire cipher fatally vulnerable.

The method exploits the presence of the so-called "cycles" in the open-closed text pair. To explain the notion of "cycle", consider the following open message P and its corresponding cryptotext C, encrypted by Enigma.

P=WETTERVORHERSAGEBISKAYA
C=RWIVTYRESXBFOGKUHQBAISE
Let's write each character from the pair in the form of a table:

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s

e

Pay attention to the substitutions implemented by enigma in 14th, 15th and 20th positions. At step 14, the letter A is encrypted into G. The latter, in turn, is encrypted into K at step 15. And then the letter K is encrypted into A at step 20, thereby looping chain A-G-K-A. Such looped chains are called cycles. The presence of cycles allows us to divide the task of breaking Enigma into two simple components: 1) finding the starting position of the rotors and 2) finding the connections of the plugboard with known rotor settings.

We know that Enigma encryption goes through several transformations. First, the signal passes through the patch panel. The result of the conversion on the patch panel enters the rotors. After that, the signal hits the reflector and returns through the rotors to the patch panel, where the last substitution is performed. All these operations can be represented by a mathematical formula:
E i = S -1 R -1 TRS, where
S and S -1 , - transformation on the patch panel at the input and output, respectively;
R and R -1 - transformation in the rotors at the input and output;
T - transformation on the reflector.
Omitting the plugboard, we express the internal transformation of Enigma in terms of P i:
P i \u003d R -1 TR
Now encryption can be written as:
E i \u003d S -1 P i S

Using the formula, we will rewrite the substitutions from the example in 14, 15 and 20 positions.
S -1 P 14 S(A) = G or what is the same P 14 S(A) = S(G).
P 15 S(G) = S(K)
P 20 S(K) = S(A)
Replacing S(K) in the last expression, we get:
P 20 P 15 P 14 S(A) = S(A) (1) where S(A) is the letter connected to A on the patch panel.
Now the attack is reduced to a trivial enumeration of all possible installations rotor. For each combination of rotors, it is necessary to check the fulfillment of equality (1). If the equality is true for the letter S, it means that the correct configuration rotors and that the letter A is connected to the letter S on the patch panel. The search for the remaining pairs comes down to deciphering the cryptotext by letter and comparing the result with the known plaintext.
It should be noted that with a probability of 1/26, the equality can be fulfilled even if the rotors are incorrectly installed, therefore, to increase the reliability of the algorithm, it is desirable to use several “cycles”.
Another important point is related to the fact that an attacker may know only a part of the encrypted message. And in this case, first of all, he will need to find the location of the known text in the received cryptogram. Knowing the fact that Enigma never encrypts a letter into itself helps a lot in solving this problem. Those. to find the correct offset, you need to find such a position in the cryptotext at which none of the letters of the private text is duplicated by the letter of the open message.

P.S.

A very slow, but quite working implementation of the attack on Python can be viewed at

The most common encryption method in the Red Army during the Great Patriotic War there were crossover codes. There was a certain hierarchy of their use: 2-digit codes were used by the lower echelons of the armed forces, 3-digit ones were in use in units up to the brigade level, 4-digit ones were intended for armies and fronts, and finally, the highest 5-digit code was used only for encrypting strategic information of the high level. Border guards, internal and railway troops used their own code systems, and the structure of the Ministry of Foreign Affairs used mainly the mentioned 5-digit codes. It was the 5-digit codes that turned out to be the most persistent - throughout the war, neither enemies, nor neutrals, nor allies could read such ciphers Soviet Union. But other, less complex systems, turned out to be quite tough for the cryptanalysts of Nazi Germany.

From May 1943, for a year, a decryption unit worked in Army Group North, which received more than 46,000 intercepted messages encoded in 4-, 3-, and 2-digit codes. From this sea of ​​information, a little more than 13 thousand were hacked, that is, about 28.7% of the total volume. Interestingly, the Germans naturally focused on 4-digit ciphers, hoping that it was in such dispatches that the most valuable information would be hidden. The significance of the operational information obtained in this way is clearly described by one of the reports of the German codebreakers on their work in February 1944: These messages made it possible to identify seven tank units and their numbers and establish the presence of another twelve tank units. With rare exceptions, this material was processed in a timely manner, and the information received was used in practice.

The text of the Soviet military cryptogram translated into German, deciphered by the cryptanalysts of Army Group North

In fairness, it should be noted that these transcripts had the status of tactical, since the Germans could not get access to strategic data until the very end. In this regard, one German codebreaker once said: “Russia lost the First world war on the air and won World War II there.

A certain disadvantage of actually manual encryption was the huge time spent on encryption and further decryption, which sometimes led to tragedies. Yes, boss General Staff The Red Army Georgy Konstantinovich Zhukov on June 21, 1941 at 17.00 receives an order from Stalin and Timoshenko to put the troops on high alert. It took several hours to write, encrypt and send the directives to the Western military districts, and, as President of the Academy of Military Sciences Makhmut Gareev writes, “many formations did not receive any orders at all, and bursts of enemy shells and bombs became a combat alarm signal for them.” Such tragic sluggishness was called upon to exclude the subsequent orders of the People's Commissariat of Defense under the numbers 375, 0281 and 0422. In this regard, the instruction of the People's Commissar of the Navy Nikolai Gerasimovich Kuznetsov is exemplary, in which at 2 hours 40 minutes on June 22, 1941 he wrote extremely concisely: " Operational readiness No. 1. Immediately". As a result, the fleets met the aggression of fascist Germany fully armed. The leadership of the Navy in general was especially reverent about working with classified data: on July 8, 1941, the “Instruction on measures to preserve military secrets (for wartime)” was introduced (Order of the People's Commissariat navy №0616).

Wartime required new solutions in the field of information security. In 1942, a cryptographic council began work in the 5th Directorate of the NKVD, which during the war carried out work on 60 special topics related to encryption. The leadership of the Red Army carried out active work in the direction of regulating the work of the encryption service. With a slight delay, but in 1942, a number of special NPO orders were nevertheless issued: No. 72 on the procedure for sending secret correspondence and No. 014, together with No. 0040, on conducting closed telephone conversations, radio and telegraph transmissions. Already in 1943, the "Manual on the cipher-staff service in the Red Army" went to the army units.

Georgy Konstantinovich Zhukov

In any narrative about the encryption business of Soviet specialists of the Great Patriotic War, one cannot do without the reviews of our illustrious commanders. So, Georgy Zhukov wrote in this regard: "The good work of cryptographers helped win more than one battle." Marshal Alexander Vasilevsky recalls in his memoirs: “Not a single report on the upcoming military-strategic operations of our army became the property of fascist intelligence. Being the chief of the General Staff, I could not do a single minute without high-frequency communications, which, thanks to the high consciousness and skill of signalmen the best way provided operational leadership of the active fronts and armies. Marshal Ivan Konev also praised the level of communication during the war years: “It must be said in general that this high-frequency communication, as they say, was sent to us by God. She helped us out so much, she was so stable in the most difficult conditions that we must pay tribute to our technology and our signalmen, who specially provide this HF connection and in any situation literally follow on the heels of those who are supposed to use this connection when moving. “Without high-frequency communications, not a single significant military action was launched or carried out. HF communications provided not only headquarters, but also the command directly on the front lines, at sentinel posts, bridgeheads. In the Patriotic War, high-frequency communications played an exceptional role as a means of command and control and contributed to the implementation of military operations, ”Marshal Ivan Bagramyan spoke about the role of high-frequency communications in the war.

Statistical calculations speak very eloquently of the scale of the work of Soviet signalmen: 66,500 km of overhead communication lines were restored and built, 363,200 km of wires were suspended and 33,800 km of pole lines were built. By the end of the Patriotic War, signalmen served almost 33 thousand km of HF communication lines, and by September 1945, almost 37 thousand km. During the war with fascist Germany, such samples of classification technology as Sobol-D, Baikal, Sinitsa, MES-2, SI-16, SAU-14, Neva- C" and SHAF-41. More than 20 thousand soldiers and officers of the government communications troops were awarded medals and orders, 837 servicemen did not return from the front, 94 are missing ...

Probably, one of the most significant assessments of work at the front are the reviews of the opposing side. Jodl, during an interrogation on June 17, 1945, reported: “The bulk of intelligence on the course of the war - 90 percent - was radio intelligence materials and interviews of prisoners of war. Radio intelligence - both active interception and decryption - played a special role at the very beginning of the war, but until recently it did not lose its significance. True, we have never been able to intercept and decipher the radio messages from your headquarters, the headquarters of the fronts and armies. Radio reconnaissance, like all other types of reconnaissance, was limited only to the tactical zone.

Battle of Stalingrad

The most interesting thing is that the Headquarters often completely abandoned the procedure for encrypting information for transmission over communication networks. So, during the preparation of the counteroffensive near Stalingrad, a directive was issued to the front commander:

"Bid Supreme High Command categorically forbids you from now on to send in cipher any considerations on the plan of operation, to issue and send out orders on upcoming actions. All plans for the operation, at the request of the Headquarters, should be sent only handwritten and with the responsible executor. Orders for the upcoming operation should be given by the commanders of the armies only personally on the map.

In fact, most of the issues of the counterattack were personally decided by the representatives of the Stavka Vasilevsky and Zhukov, who were present at the fronts. Moreover, before the offensive itself, the Headquarters sent a number of directives to the fronts by direct wire and in unencrypted form. They spoke of the cessation of all offensive operations and the transition of the fronts to a tough defense. This disinformation reached the Germans, reassured them, which became one of the decisive factors in the success of the operation.

The first monument in Russia in honor of military signalmen was opened on May 11, 2005 in the memorial complex of the heroes of the Great Patriotic War in Mozhaisk

Work under the heading of "special importance" on the fronts great war did not remain in the shadow of oblivion, the feat of Russian cryptographers is not forgotten and will live on in our days and in the future. A new round of domestic encryption service happened after 1945. It is no less interesting to study.

According to materials:
Bykhovsky M. A. Circles of memory. Essays on the history of the development of radio communications and broadcasting in the twentieth century "- M .: International Center for Scientific and Technical Information, Mobile Communications LLC.
Dadukov N. S., Repin G. A., Skachkov M. M., Filin Yu. P. Soviet encryption technology. Leningrad period: 1935–1941. Part 4
Expansion of the nomenclature of encryption technology // Protection of information. Inside. No. 4.
Pavlov VV From the history of the creation and development of the government telecommunications system of the Soviet state (1930–1941).
Shannon K. Works on information theory and cybernetics.
Yatsevsky A. A. The state and development of military communications in the USSR on the eve of the Great Patriotic War.

Wars are fought with weapons. However, only weapons are not enough. Whoever has the information wins! You need to get someone else's information, and protect your own. This particular kind of struggle is going on all the time.

The ancient Egyptians protected their secrets with hieroglyphic ciphers, the Romans with the Caesar cipher, the Venetians with Alberti cipher discs. With the development of technology, the flow of information increased, and manual encryption became a serious burden, and did not provide proper reliability. There were encryption machines. The most famous among them is Enigma, which became widespread in Nazi Germany. In fact, Enigma is a whole family of 60 electromechanical rotary encryption devices that worked in the first half of the 20th century in commercial structures, armies and services in many countries. A number of books and films such as the Hollywood blockbuster Enigma introduced us to the German military Enigma (Enigma Wehrmacht). She has a bad reputation, because English cryptanalysts were able to read her messages, and the Nazis got it sideways.

In this story there were brilliant ideas, unique achievements of technology, the most complex military operations, disregard for human lives, courage, betrayal. She showed how the ability to anticipate the actions of the enemy neutralizes the brute force of the weapon.

The appearance of "Mystery"

In 1917, the Dutchman Koch patented an electric rotary encryption device to protect commercial information. In 1918, the German Scherbius bought this patent, finalized it and built the Enigma cipher machine (from the Greek ανιγμα - “mystery”). Having created the company Chiffriermaschinen AG, the businessman from Berlin began to raise demand for his not yet secret novelty, exhibiting it in 1923 at the international postal congress in Bern, a year later - in Stockholm. The "riddle" was advertised by the German press, radio, the Austrian Institute of Criminology, but there were almost no people who wanted to buy it - it was a little expensive. Piece "Enigma" went to Sweden, the Netherlands, Japan, Italy, Spain, USA. In 1924, the British took the car, registered it with their patent office, and their cryptographic service (Room 40) looked into its insides.

And they are simple. This is a kind of electric typewriter: a keyboard for 26 letters of the Latin alphabet, a register for 26 light bulbs with letters, a patch panel, a 4.5 volt battery, a coding system in the form of rotors with encryption disks (3-4 working plus 0-8 replaceable). The rotors are interconnected like gears in an odometer (car odometer). But here, in contrast to the odometer, the rightmost disk, when entering a letter, rotates by a variable step, the value of which is set according to the schedule. Having made a full turn, it transfers the turn by a step to the next rotor, etc. The right disk is the fastest, and the gear ratio of the gearbox is variable, i.e. the switching scheme changes with each letter entered (the same letter is encrypted in differently). The rotors are marked with an alphabet, which allows you to change their initial setting according to predetermined rules. The highlight of Enigma is a reflector, a statically fixed rotor, which, having received a signal from rotating rotors, sends it back and in a 3-rotor machine the signal is converted 7 times.
The operator works like this: he presses the key with the next letter of the encrypted message - the lamp corresponding (only at the moment!) To this letter lights up on the register - the operator, seeing the letter on the lamp, enters it into the encryption text. He does not need to understand the encryption process, it is done completely automatically. The output is complete abracadabra, which goes away as a radiogram to the addressee. It can only be read by "one of your own" who has a synchronously tuned "Enigma", i.e. who knows exactly which rotors and in what order are used for encryption; his machine decrypts the message automatically, too, in reverse order.
The "riddle" dramatically accelerated the communication process, eliminating the use of tables, cipher notebooks, transcoding logs, long hours of painstaking work, and inevitable errors.
From the point of view of mathematics, such encryption is the result of permutations that cannot be traced without knowing the starting position of the rotors. The encryption function E of the simplest 3-rotor Enigma is expressed by the formula E = P (pi Rp-i) (pj Mp-j) (pk Lp-k)U (pk L-1 p-k) (pj M-1 p-j) ( pi R-1 p-i) P-1, where P is the plugboard, U is the reflector, L, M, R are the actions of the three rotors, the middle and left rotors are j and k rotations of M and L. After each keystroke, the transformation changes .
Enigma was quite simple and reliable for its time. Her appearance puzzled none of Germany's possible adversaries, except for Polish intelligence. The German military and the Foreign Ministry, ignoring the novelty, continued to work manually (ADFGX method, code books).
And then in 1923 the British Admiralty released The History of the First World War, telling the whole world about their advantage in that war thanks to breaking the German code. In 1914, the Russians, having sunk the German cruiser Magdeburg, fished out the corpse of an officer clutching a magazine with a naval code to his chest. The discovery was shared with an ally England.

The German military elite, having experienced shock and analyzed the course of hostilities after that incident, concluded that such a fatal leak of information should no longer be allowed. "Enigma" immediately became in demand, massively purchased by the military, disappeared from free sale. And when Hitler started cooking new war, the encryption miracle was included in the mandatory program. Increasing the security of communication, the designers constantly added new elements to the machine. Even in the first 3-rotor model, each letter has 17576 variants (26x26x26). When using 3 out of 5 working rotors in random order, the number of options is already 1054560. The addition of the 4th working rotor complicates encryption by orders of magnitude; when using interchangeable rotors, the number of options is already measured in the billions. This convinced the German military.

Blitzkrieg gun

Enigma is just one type of electromechanical disk encoder. But here is its mass character ... From 1925 until the end of World War II, about 100 thousand cars were produced.
This is the whole point: the encryption technology of other countries was piecemeal, working in the special services, for behind closed doors. "Enigma" - a blitzkrieg weapon - fought in the field at levels above the division, on board a bomber, ship, submarine; was in every port, on every major railway. station, in every SS brigade, every Gestapo headquarters. Quantity turned into quality. A not too complicated device became a dangerous weapon, and the fight against it was fundamentally more important than the interception of a separate, even very secret, but still not mass correspondence. Compact in comparison with foreign counterparts, the car could be quickly destroyed in case of danger.

The first - Model A - was large, heavy (65x45x35 cm, 50 kg), similar to a cash register. Model B already looked like an ordinary typewriter. The reflector appeared in 1926 on a truly portable Model C (28x34x15 cm, 12 kg). These were commercial devices with encryption without much resistance to hacking, there was no interest in them. It appeared in 1927 with the Model D, which then worked on the railway and in occupied Eastern Europe. In 1928, Enigma G appeared, aka Enigma I, aka Wehrmacht Enigma; having a patch panel, it was distinguished by enhanced cryptographic resistance and worked in ground forces and Air Force.
But the first "Enigma" began to use the German Navy. It was a Funkschlüssel C model from 1925. In 1934, the fleet adopted a naval modification of the army vehicle (Funkschlüssel M or M3). The army team used only 3 rotors at that time, and in the M3, for greater safety, it was possible to choose 3 out of 5 rotors. 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 massive "Enigma" M4 was the most protected. She had a printer (Schreibmax) as a remote panel in the commander's cabin, and the signalman worked with ciphertext, without access to secret data.
But there was also special-special equipment. Abwehr (military intelligence) used the 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), Abwehr abandoned the patch panel. As a result, the British managed to break into the protection of the machine, which greatly complicated the work of German agents in Britain. "Enigma T" ("Tirpitz Machine") was created specifically for communication with an ally, Japan. With 8 rotors, reliability was very high, but the machine was hardly used. Based on the M4, the M5 model was developed with a set of 12 rotors (4 working / 8 replaceable). And on the M10 there was a printer for open / closed texts. Both machines had another innovation - a rotor for filling gaps, which greatly increased the reliability of encryption. The Army and Air Force encrypted messages in groups of 5 characters, the Navy - 4 characters each. To complicate the deciphering of intercepts by the enemy, the texts contained no more than 250 characters; long ones were broken into pieces and encrypted with different keys. To increase protection, the text was clogged with "garbage" ("letter salad"). It was planned to rearm all types of troops on the M5 and M10 in the summer of 1945, but time has passed.

"Rejewski's bomb"

So, the neighbors were "blinded" about Germany's military preparations. The activity of the radio communications of the Germans increased many times over, and it became impossible to decipher the intercepts. The Poles were the first to be alarmed. Watching a dangerous neighbor, in February 1926 they suddenly could not read the codes of the German Navy, and since July 1928, the codes of the Reichswehr. It became clear: they switched to machine encryption. On January 29, the Warsaw customs found a “lost” parcel. Berlin's tough request to return it drew attention to the box. There was a commercial "Enigma". Only after studying it was given to the Germans, but this did not help to reveal their tricks, and they already had a reinforced version of the car. Especially for the fight against Enigma, Poland's military intelligence created a "Cipher Bureau" from the best mathematicians who spoke fluent German. They were lucky only after 4 years of marking time. Luck came in the person of an officer of the German Ministry of Defense, "bought" in 1931 by the French. Hans-Thilo Schmidt ("agent Ashe"), responsible for the destruction of obsolete codes of the then 3-rotor Enigma, sold them to the French. Got them and instructions for it. The ruined aristocrat needed money and was offended by his homeland, which did not appreciate his merits in the First World War. French and British intelligence did not show any interest in this data and handed it over to the Polish allies. In 1932, the talented mathematician Marian Rejewski and his team hacked into the miracle machine: "Ashe's documents became manna from heaven: all the doors opened instantly." France supplied the Poles with agent information until the war itself, and they managed to create an Enigma imitator machine, calling it a “bomb” (a popular ice cream variety in Poland). Its core was 6 Enigmas connected to a network, capable of sorting through all 17576 positions of three rotors in 2 hours, i.e. all possible key options. Her strength was enough to open the keys of the Reichswehr and the Air Force, but it was not possible to split the keys of the Navy. "Bombs" were made by AVA Wytwurnia Radiotechniczna (it was she who 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 one “bomb” each. The French, crushed by the Wehrmacht, lost the car, but the British made a more advanced cyclometer machine out of theirs, which became the main tool of the Ultra program. This Enigma counter-program was Britain's best-kept secret. The messages decrypted here were labeled Ultra, which is higher than Top secret.

Bletchley Park: Station X

After the First World War, the British reduced 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 drove into the Bletchley Park estate 50 miles from London under the guise of a company of hunters. Here, in the decryption center Station X, which was under the personal control of Churchill, all information from radio intercept stations in the UK and beyond converged. The British Tabulating Machines built here the first Turing bomb decryption machine (this was the main British cracker), the core of which was 108 electromagnetic drums. She went through all the options for the cipher key with a known structure of the decrypted message or part of the plaintext. Each drum, rotating at a speed of 120 revolutions per minute, tested 26 letter variants in one complete revolution. During operation, the machine (3.0 x2.1 x0.61 m, weight 1 ton) ticked like a clockwork, which confirmed its name. For the first time in history, the ciphers mass-produced by the machine were solved by the machine itself.

"Enigma" auf U-Boot U-124

To work, it was necessary to know the physical principles of the Enigma to the smallest detail, and the Germans constantly changed it. The British command set the task: by all means to get new copies of the machine. A targeted hunt began. First, on a Junkers shot down in Norway, they took the Enigma-Luftwaffe with a set of keys. The Wehrmacht, smashing France, advanced so quickly that one communications company overtook its own and was captured. The Enigma collection was replenished with the army one. They were dealt with quickly: Wehrmacht and Luftwaffe ciphers began to fall on the table of the British headquarters almost simultaneously with the German one. Desperately needed the most complex - the marine M3. Why? The main front for the British was the sea front. Hitler tried to strangle them with a blockade, blocking the supply of food, raw materials, fuel, equipment, and ammunition to the island country. His weapon was the submarine fleet of the Reich. The group tactics of the “wolf packs” terrified the Anglo-Saxons, their losses were huge. They knew about the existence of the M3: 2 rotors were captured on the U-33 submarine, and instructions for it on the U-13. During a commando raid on the Lofoten Islands (Norway), aboard the German Crab patrol, they captured 2 rotors from the M3 and the keys for February, the Germans managed to drown the car. Moreover, quite by accident it turned out that German non-military ships were sailing in the Atlantic, carrying special communications on board. So, the destroyer of the Royal Navy "Griffin" inspected the supposedly Dutch fishing vessel "Polaris" off the coast of Norway. The crew, which consisted of strong guys, managed to throw two bags overboard, 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. They had Enigma on board and settings for every day for 2-3 months, depending on the duration of the voyage. They regularly transmitted the weather, and it was easy to find them. Special operational groups of the Royal Navy came out to intercept the "meteorologists". Fast destroyers literally took the enemy "on the gun." Shooting, they tried not to sink the "German", but to drive his crew into a panic and prevent the destruction of special equipment. On May 7, 1941, the Munich trawler was intercepted, but the radio operator managed to throw the Enigma and the May Keys overboard. But in the captain's safe, they found the keys for June, a short-range cipher book, a weather code log, and a Navy coordinate grid. To conceal the capture, the English press wrote: "Our ships in the battle with the German" Munich "captured its crew, which left the ship, flooding it." Mining helped: the time from intercepting a message to decrypting it was reduced from 11 days to 4 hours! But now the keys expired, new ones were needed.

Captain Lemp'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, Lieutenant Commander Julius Lemp, who attacked convoy OV-318. Having bombed U-110, the escort ships forced her to surface. The captain of the destroyer HMS Bulldog went to ram, but when he saw that the Germans were jumping overboard in a panic, he turned away in time. Entering the half-submerged boat, the boarding party discovered that the crew had not even attempted to destroy the secret communications equipment. At this time, another ship picked up the surviving Germans from the water and locked them in the hold to hide what was happening. It was very important.
On the U-110 they took: a serviceable Enigma M3, a set of rotors, keys for April-June, encryption instructions, radiograms, magazines (personnel, navigation, signal, radio communications), sea charts, minefield diagrams in the North Sea and coast of France, instruction manual for type IXB boats. The booty was compared with the victory in the Battle of Trafalgar, experts called it "a gift from heaven." The awards to the sailors were presented by King George VI himself: “You deserve more, but now I can’t do it” (through the award system, German agents could have come to the fact of the loss of the car). A subscription was taken from everyone, the capture of U-110 was not disclosed until 1958.
The gutted boat was sunk for the sake of secrecy. Captain Lemp is dead. Interrogation of the rest of the Germans revealed that they were unaware of the loss of the secret. Just in case, measures were taken to misinform, with the prisoners they complained and regretted: "It was not possible to land on the boat, it suddenly sank." For the sake of secrecy, they even coded her capture: "Operation Primula." Shocked by his success, the First Sea Lord Pound radioed: “Congratulations from the bottom of my heart. Your flower of rare beauty.
Trophies from the U-110 brought a lot of good. With the latest information, the Bletchley Park burglars began to regularly read the communications between the Reich submarine headquarters and the boats in the ocean, cracking most of the messages protected by the Hydra cipher. This helped to open other codes of the Navy: “Neptune” (for heavy ships), “Zuid” and “Medusa” (for the Mediterranean Sea), etc. It was possible to defeat the German network of reconnaissance and supply vessels for the submarine fleet (“cash cows” in the Atlantic). ). The operational intelligence center found out the details of the coastal navigation of the Germans, mining schemes for coastal waters, the timing of submarine raids, etc. Sea convoys began to bypass the “wolf packs”: from June to August, the “Doenitz wolves” found only 4% of the convoys in the Atlantic, from September to December - 18%. And the Germans, believing that the U-110 had taken their secret into the abyss, did not change the communication system. Admiral Dönitz: "Lemp did his duty and died like a hero." However, after the release of Roskilde's book The Secret Capture in 1959, the hero became in the eyes of German veterans a scoundrel who tarnished his honor: “He did not comply with the order to destroy secret materials! Hundreds of our boats were sunk, thousands of submariners died in vain”, “if he hadn’t 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 hit the wall again. It remained to hope for the capture of a new car, which happened on October 30, 1942. On this day, Lieutenant Commander Heidtmann's U-559, northeast of Port Said, was badly damaged by British depth charges. Seeing that the boat was sinking, the crew jumped overboard without destroying the encryption technology. She was found by sailors from the destroyer Petard. As soon as they handed over the prey to the boarding group that came to the rescue, the mangled boat suddenly turned over, and two daredevils (Colin Grazier, Antony Fasson) went with it to a kilometer depth.
The booty was the M4 and the "Short Call Sign Log"/"Short Weather Code" pamphlets, printed with solvent ink on pink blotting paper, which the radio operator must 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 black-out, the reading of ciphergrams began again, which was not interrupted 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 clothes were taken away in order to search for documents of interest for intelligence (for example, the code tables of the Enigma cipher machine).

A whole technology of such operations has been developed. The boat was forced to surface with bombs and started shelling from machine guns so that the Germans, remaining on board, would not start flooding. In the meantime, a boarding party was heading towards it, aiming to look for “something like a typewriter next to the radio station”, “discs 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 getting anything new.
In total, the British captured 170 Enigmas, including 3-4 naval M4s. This made it possible to speed up the decryption process. With the simultaneous inclusion of 60 "bombs" (i.e. 60 sets of 108 drums), the search for a solution was reduced from 6 hours to 6 minutes. This already made it possible to respond quickly to revealed information. At the peak of the war, 211 "bombs" worked around the clock, reading up to 3 thousand German ciphers 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 intercepts, some of the work was transferred to the United States. By the spring of 1944, 96 "Turing bombs" were working there, and an entire decryption factory had appeared. In the American model, with its 2000 rpm, respectively, the decryption was 15 times faster. Confrontation with the M4 has become a routine. Actually, this is where the fight against Enigma ended.

Consequences

Breaking the Enigma codes provided the Anglo-Saxons with access to almost all the secret information of the Third Reich (all armed forces, SS, SD, Foreign Ministry, post office, transport, economy), gave great strategic advantages, helped to win victories with little bloodshed.
"Battle of Britain" (1940): Hardly fending off German air pressure, in April the British began to read Luftwaffe radio messages. This helped them properly manage their last reserves, and they won the battle. Without the Enigma hack, a German invasion of England would have been very likely.
"Battle of the Atlantic" (1939-1945): not taking the enemy from the air, Hitler strangled him with a blockade. In 1942, 1006 ships were sunk with a displacement of 5.5 million gross tons. It seemed that just a little bit more and Britain would fall to its knees. But the British, reading the cipher communication of the "wolves", began to drown them mercilessly and won the battle.
Operation Overlord (1945): before the landing in Normandy, the Allies knew from the transcript about ALL German countermeasures to repel the landing, every day they received accurate data on the positions and defense forces.
The Germans constantly improved the Enigma. Operators were trained to destroy it in case of danger. During the war, the keys were changed every 8 hours. Cipher documents dissolved in water. The creators of the "Riddle" were also right: it is impossible in principle to decipher its messages manually. But what if the enemy opposes this machine with his own? But he did just that; capturing new copies of technology, he improved his "anti-Enigma".
The Germans themselves facilitated his work. So, they had an “indicator procedure”: at the beginning of the ciphergram, a setting was sent twice (number of rotors / their starting positions), where a regular similarity between the 1st and 4th, 2nd and 5th, 3rd and 6 characters. The Poles noticed this as early as 1932 and cracked the code. Weather reports were a significant security flaw. The divers received them from the base "securely" encrypted. On land, the same data was encrypted in the usual way - and now the crackers already have a set of known combinations in their hands, and it is already clear which rotors work, how the key is built. Decoding was facilitated by the standard language of messages, where expressions and words were often repeated. So, every day at 6:00 the weather service gave an encrypted forecast. The word "weather" was obligatory, and the clumsy German grammar put it in its exact place in the sentence. Also: the Germans often used the words "vaterland" and "reich". The British had employees with native German (native speakers). Putting themselves in the place of the enemy cipher clerk, they went through a lot of ciphers for the presence of these words - and brought the victory over Enigma closer. It also helped that at the beginning of the session, the radio operator always indicated the call sign of the boat. Knowing all their call signs, the British determined the rotary scheme, obtaining approximate cipher combinations of some characters. "Coercive information" was used. So, the British bombed the port of Calais, and the Germans gave an encryption, and in it - already known words! Decryption was facilitated by the laziness of some radio operators, who did not change the settings for 2-3 days.

The Nazis were let down by a penchant for complex technical solutions where it was safer to get by with simpler methods. They didn't even know about the Ultra program. Fixated on the idea of ​​Aryan superiority, they considered the Enigma impenetrable, and the knowledge of the enemy - the result of espionage and betrayal. They managed to get into the London-Washington government communications network, read all the intercepts. Having revealed the codes of sea convoys, they directed "wolf packs" of submarines at them, which cost the Anglo-Saxons 30,000 lives of sailors. However, with an exemplary order in the organization of affairs, they did not have a single decryption service. This was done by 6 departments, not only not working together, but also hiding their skills from fellow competitors. The communication system for resistance to hacking was evaluated not by cryptographers, but by technicians. Yes, there were investigations into the suspicions of a leak along the Enigma line, but the specialists could not open the eyes of the authorities to the problem. “The Reich’s chief submariner, Admiral Doenitz, never understood that it was not radar, not direction finding, but reading cipher messages that made it possible to find and destroy their boats” (post-war report by the Army Security Agency / USA).
It is said that without the cracking of the Nazis' master cipher machine, the war would have lasted two years longer, cost more sacrifices, and may not have been ended without atomic bombing Germany. But this is an exaggeration. Of course, it is more pleasant to play by looking at the opponent's cards, and deciphering is very important. However, she did not defeat the Nazis. Indeed, from February to December 42, without having a single decryption, the Allies destroyed 82 German submarines. And on land, the Germans in a huge number of operations sent information by wire, courier, dogs or pigeons. During the Second World War, half of all information and orders were transmitted in such ways.
... In the summer of 1945, the guys from TICOM (Target Intelligence Committee, Anglo-American office for the seizure of German information technology) confiscated and took out the latest Enigmas and specialists in them. But the car (Schlüsselkasten 43) continued to be produced: in October - 1000, in January of the 46th - already 10,000 pieces! Its hacking remained a secret, and the myth of the absolute reliability of the product of "German genius" has spread all over the planet. Thousands of Enigmas were sold by the Anglo-Saxons to dozens of countries of the British Commonwealth of Nations on all continents. They worked there until 1975, and the "benefactors" read the secrets of any government.
Enigma was used by many: the Spaniards - commercial, the Italian Navy - Navy Cipher D, the Swiss - Enigma K. The Japanese clone of Enigma was the 4-rotor GREEN. The British made their Typex according to the drawings and even from the details of the Enigma, pirated using the patent.
Today, there are up to 400 working copies of Enigma in the world, and anyone who wishes can purchase it for 18-30 thousand euros.

Chatterbox will be shot!

The effort to cover up the Ultra program was unprecedented. After gutting, German ships and submarines were sunk so that the enemy would not guess about their capture. The prisoners were isolated for years, their letters home were intercepted. Their sailors-talkers were exiled to serve in darkness like the Falkland Islands. The received intelligence was refined / distorted, and only then transferred to the troops. The full mastery of the "Riddle" was hidden throughout the war, even from the "big brother" of the United States. Knowing from the encryption about the forthcoming bombing of Coventry on November 14, 1940, the population of the city was not evacuated so that the Germans would not guess that they were being “read”. It cost the lives of half a thousand citizens.
At the height of the war, up to 12 thousand people worked in the Ultra program: mathematicians, engineers, linguists, translators, military experts, chess players, puzzle specialists, operators. Two-thirds of the staff were wrens (Women's Royal Naval Service) female soldiers. While doing their tiny part of the job, no one knew what they were doing in general, and the word "Enigma" had never been heard. People who did not know what was happening behind the next door were constantly reminded: "For chatting about work - execution." Only 30 years later, after the removal of secrecy, some of them dared to admit what they did during the war. A. Turing wrote a book about breaking Enigma: the British government did not allow its release until 1996!
The Nazis did not have their own "mole" in Bletchley Park. But for the USSR, what was happening there was no secret. Moscow received small doses of information of the "ultra" category on the direct orders of Churchill, despite the protests of his headquarters. In addition, British intelligence officer John Cairncross, who had access to classified data, supplied the Russians with them without restriction, including Enigma decryptions.

The success of the Enigma crackers was based on just a few brilliant ideas that came out at the right time. Without them, Enigma would have remained a Riddle. Stuart Milner-Berry, British chess champion, one of the main burglars of Bletchley Park: "There has been no such example since ancient times: the war was conducted in such a way that one opponent could constantly read the most important messages of the army and navy of the other."
After the war, the "Turing bombs" were destroyed for security reasons. After 60 years, the Enigma & Friends society tried to recreate one of them. Only the assembly of components took 2 years, and the assembly of the machine itself took 10 years.