Two months later, in the face of the still bitter cold wind, the German General Staff delegation once again boarded the train to Bavaria. This time, a series of senior officials, including the Chief of Staff Earl Schliffen and Moltke, as well as the Minister of the Prussian War, almost all participated in the delegation, and the lineup was unprecedentedly powerful. The group came to Munich, the capital of Bavaria, with a sense of loss and a hint of anger. On the next day, the prince and relevant personnel met Prussian guests who came from afar.

"Everyone, we should be happier. At least we can't exchange a little money for future victory now, right? This little money is nothing to His Majesty the Emperor and the Kingdom of Prussia. You shouldn't do that." Looking at the Count Schliffen and his party with a gloomy face, the prince quipped, since he is a loser, he must have the awareness of a loser, always be the best in the world, how can the highest idea of ​​German technology lead the development direction of advanced productivity? Arrogance is the biggest enemy of progress, why don't you understand?

"Well, okay, let's talk about the serious matters. Now, please invite Arthur Shelbius, the director of the Bavarian Secret Service and the designer of the new encryption method, to introduce this encryption method that can be called a cryptography revolution." The prince looked at the high-ranking Prussian officials in front of him and was not interested in his jokes, so he decisively began to talk about the topic.

"Dear gentlemen, military passwords have appeared on the battlefield since the era of Caesar. In the subsequent thousands of years of history, the battle between coders and crackers has never stopped. In order to ensure the confidentiality of passwords, coders have increased the confidentiality of passwords from simple replacement, complex replacement, keys, frame passwords, etc., while crackers use various methods such as distribution, guessing, stealing and buying to decipher passwords."

"But from the current situation, the crackers have the advantage, because no matter how the coder changes the way the password is written, the most basic tool they can rely on is the pen, paper and their own brain. The passwords written cannot be too complicated, because the encryptor needs to convert plain text into cipher text one by one, and the translator also needs to turn this process in reverse. The keys and complex forms that change every day make the encryption and decryption work extremely complicated. There are not many clever encryption methods in history, but unfortunately, they cannot be promoted at an older age because of the overly complex process. After all, ensuring that the information to be sent is the most basic requirement of communication!"

"With the invention of radio technology, our password encryption work has fallen into a more unfavorable situation. Our previous passwords were not transmitted through closed lines or personnel, and they are relatively safe. But now, with the spread of radio waves, anyone can easily receive our signals at the corresponding frequency, and then their crackers can crack them. Just like we did before, our actions are no secret to our opponents."

"So, if we want to develop a brand new and difficult-to-crack encryption method, we must change from the tools in our hands. Simple pencils and white paper can no longer meet the needs of the times. Secondly, we must also change the simple correspondence of classical passwords. This relationship does not only refer to one-to-one correspondence, but also to all regular and verifiable shifts and key encryption. Only by doing these two points can the existing cracking methods be completely invalid. Adhering to these two requirements, we have developed a special password machine to solve this problem!" After Arthur said that, he signaled his assistant to put a small box on the table and then opened the box.

This is something similar to a typewriter. Below is the keyboard, and in the middle is a group of light bulbs representing letters. The top set of rotors is the top. When Arthur opened the cover of this machine, complex mechanical equipment and various colors of wires leaked inside, some of which are obviously removable.

"This, this is really a precision machine." Xiao Moltke walked over and looked carefully at the structure inside. The feeling that this machine gave him was that although he didn't understand it very well, he looked very powerful.

"Are you replacing human labor through mechanical encryption and decoding? This is indeed a breakthrough that can promote many complex passwords. The sender and the receiver can quickly complete the encoding and decoding work as long as they are equipped with such a machine." For the layman watching the excitement and the expert looking at the tricks, a Prussian crypto expert quickly discovered the problem. However, due to his vision, he only saw the speed of password sending and decoding, and made the correspondence more complicated, but did not find the most essential problem, and the simple correspondence was broken.

"You are right, but it is not the key. The most important thing about this cipher machine is to make the same letters on the plain text correspond to different letters on the cipher text. As you can see, these rotors can be rotated. When I press the first letter a on the keyboard, this letter may correspond to the e on the cipher text. And after we enter 26 letters, the first rotor has been rotated for a week. If there is really a rotor at this time, then repetition will occur. Repetition is a taboo in cryptography, so we need to change it! So we added other rotors!"

"After the first rotor rotates for one week, it will drive the second rotor, so if you enter the identification of a, it may correspond to f. And so on, when there are three rotors, each rotor has 26 letters, then there will be repetition only after 26*26*26 letters. The number of letters is so huge that the length of a total of 17,576 letters can completely allow us to send most of the telegrams! So, that's why, after intercepting our telegram, you see some irregular garbled codes. If we send a book in ciphertext, just add two rotors to the back, which is enough to make the book undecipherable!" Arthur said proudly.

"These three rotors are the core of the encryption and decoding of the entire machine. When we want to encrypt, we first adjust the position of the three rotors according to the requirements. This is one of 17,576 cases. Let the other party guess at will. Then we press the letters on the keyboard according to the plain text, and the corresponding cipher text will be displayed on the light bulb. We only need to record these cipher texts and send them out, which completes the encryption. The receiver only needs to reverse the process, press the cipher text on the keyboard, and then record the plain text under the shining light bulb. This completes the deciphering. The key of this encryption machine is also very simple, which is the initial position of the three rotors!" The prince next to him added.
Chapter completed!