Chapter 240: The End of France (10)

"Your Highness."

Hedy Lamarr's voice was so soft and tender that it seemed to make one's bones soften.

"Ms. Heidi, how is the research project going?" Yannick went straight to the point. If it were another man, he might first try to win the favor of a woman with sweet words and flattery; but with his current status, he could completely skip these steps. As long as he wanted, there would be a large group of women lining up to show their courtesy to him, and maybe the length could circle the earth.

Heidi smiled. "With the current progress, it will enter the practical stage by the end of the year."

"Great." Yannick waved to the waiter not far away and brought a glass of champagne to Heidi. "That means that starting next year, our communication will become a black hole that the enemy cannot eavesdrop on!" Compared with fixed-frequency communication, frequency-hopping communication is more concealed and difficult to intercept. As long as the other party does not know the law of carrier frequency hopping, it is difficult to intercept the content of our communication.

Heidi's face was a little unnatural. "Your Highness, you also know that practicality does not mean popularization. I'm afraid it's a bit difficult to popularize it to the division level."

"..." Yannick smacked his lips in frustration. "That means the grassroots still have to use the Enigma cipher machine."

Friends who have seen the American blockbuster "U-571" know that the "Enigma" cipher machine is a cutting-edge secret that the Allies tried their best to obtain during the war, and it is the key to defeating the German Navy's submarines. History is indeed like this. For submarine warfare, especially the German Navy's "wolf pack" tactics, radio communication is the most important means for submarines to obtain information and report situations when they are active at sea, and the "Enigma" cipher machine is a device related to the security of the entire radio communication. Its importance can be imagined.

The "Enigma" cipher machine that appeared in the movie, at first glance, is a box full of complex and delicate components, and it looks a bit like a typewriter.

It uses a double letter substitution encryption method, using keyboards, rotors, jumpers, reflectors, and displays for symmetric encryption/decryption. When you press any letter on the keyboard, the letter will be converted into another letter through the keyboard-rotor-jumper-reflector-display.

For example, when you type A for the first time, light bulb B lights up, the rotor rotates one grid, and the password corresponding to each letter changes. When you type A for the second time, the letter it corresponds to may become C; similarly, when you type A for the third time, light bulb D may light up again. ——This is the key to why "Enigma" is difficult to decipher. This is not a simple substitution cipher. The same letter can be replaced by different letters at different positions in the plaintext, and the same letter at different positions in the ciphertext can represent different letters in the plaintext. The letter frequency analysis method is useless here. This encryption method is called "double substitution cipher" in cryptography.

Enigma is an encryption method that separates the algorithm and the key. The difficulty of cracking Enigma lies in not knowing the current key, including the initial position of the rotor and the jumper setting. In daily use, Enigma can be configured through a code book, prior agreement, and encrypted transmission using the previous day's key.

The German army evaluated the use of the "Enigma" cipher machine and believed that the cipher machine was easy to carry, easy to use, and more importantly, extremely secure. For the enemy, even if they had the cipher machine, they would not be able to decipher it if they could not master the keys composed of three lines of defense at the same time. Colonel Erich Folgibel, the chief of communications of the German Supreme Command, believed that "Enigma" would be the most perfect communication device for the German Wehrmacht's blitzkrieg.

Therefore, from the German High Command to the army, navy and air force, "Enigma" was widely used as a standard cipher machine. ——The Germans had every reason to believe that they had mastered the most advanced and secure communication encryption system in the world at that time, which was an unbreakable cipher system.

However, such foolish confidence in the machine will only lead to the bitter fruit brought by the machine in the end.

The first to crack Enigma were the Poles, who managed to get a commercial Enigma machine (usually used by the military as a commercial machine, the German army was really confident in its own encryption technology). Two Polish mathematicians led a group of assistants and after several years of hard work, they finally successfully deciphered 75% of the "Enigma" cipher messages at the end of 1937.

However, the German military improved the "Enigma" and increased it to 5 rotors. The Poles could not conquer the Germans' new "Enigma" machine until the eve of World War II.

The extremely foresighted Polish Intelligence Agency knew that Poland would definitely fall. In order to resist the common cause of Germany, it decided to send their "Enigma" cipher machine and related research materials to Britain and France, and placed the hope of defeating Hitler on these two major European powers.

Britain attached great importance to the plan provided by Poland, and even expanded the cipher team for information security.

The area of ​​the Cipher Bureau was expanded from Room 40 to Bletchley Park, which was several dozen times larger. The number of staff members increased from more than 20 to more than 9,000 five years later.

At the same time, the structure of the staff also changed. In the past, it was mainly linguists, but now it is mainly mathematicians. The Polish specifically asked the British to recruit a large number of mathematicians.

Everyone knows what happened next. Although Alan Turing admired the wisdom of the Poles, he realized that the Polish cracking method was overly dependent on the German loopholes. Later, the German army upgraded the Enigma machine, and this cracking method became ineffective. So Turing pursued a more direct and violent cracking method: machine against machine. If the Poles used loopholes in the enemy's defense line to launch a surprise attack by paratroopers, then what Turing wanted was more like a direct confrontation with the infantry division. The code monster created by the machine can only be defeated by the machine. And the task of humans is nothing more than designing the working principle of the machine and optimizing the amount of calculations to be performed by the machine.

On March 14, 1940, the first Turing "bomb" was put into use at Bletchley Park. Soon, it successfully deciphered the first Enigma code intelligence. When Winterbottom personally presented this intelligence to the Director of Air Force Intelligence, Madhurst, he excitedly said: "From now on, the Germans' top-secret intelligence is completely a book that we can read."

The Enigma code gradually became the most lethal weapon in the hands of the British. In the subsequent decisive military operations such as the Battle of El Alamein, the capture of Sicily, and the Normandy Landing, the British and the Allied forces seized the initiative on the battlefield in a timely manner by deciphering the Enigma code, which gradually tilted the balance of victory and defeat to the Allied side.

Yannick would certainly not repeat this stupid mistake. Although Alan Turing is now in Germany, he can't guarantee that there will be no other people in the UK who can crack the Enigma cipher machine, so he tried every means to improve the Enigma machine and increase the difficulty of cracking it.

Heidi asked. "Your Highness, have I completed my mission?"

Yannick smiled. "Of course, you have done a good job, and I will naturally not break my promise. But the scene of this movie will be very grand, and it is impossible to start shooting at this time. We have to wait until the end of the war."