I have to admit that the appearance of the Enig cipher machine is definitely a special mention in the history of intelligence! It was the first to make the transition from simple to complex substitutions of coding, and the cipher machine was invented in 1918 and the first prototype was produced in 1920. And at first, the inventor Arthur Shelbius wanted to sell this cipher machine to merchants, but the high price discouraged many merchants. (Converted to the current price, it is about $30,000 per unit!) ）

But then when the Germans learned from a British newspaper that their own codes had been deciphered by the British and French in World War I, Germany then began to vigorously strengthen radio security, and at this time, the Enig cipher machine officially entered the field of vision of the German government. And officially in 1925 began to order a large number of modified machines from the factory of Shelbius. And in 1926 began to equip the army with this machine. From then on, for quite some time, the British and French spy services were unable to decipher the radio communications of the Germans.

But there has never been an impenetrable defense in the world, and there has never been a password that cannot be unlocked. All sorts of accidental and inevitable factors will inevitably lead to the leakage of secrets. First of all, the first problem with the decipherment of the Enig cipher machine is that Britain, France and other countries have figured out the principle of the Enig cipher machine and completed the copying. First of all, the British got a commercial type, but the commercial type itself and the military type were different in terms of internal settings, so in the end it was fruitless.

Then, on November 8, 1931, a German communications officer named Schmidt connected with the French and sold the French the internal line diagram and instructions for the use of the military type of Enig cipher machine to the French for 10,000 marks. (The reason for this person to provide information turned out to be revenge on society because of poverty caused by the economic crisis!) And then the French finally had the ability to make a cipher machine. However, being able to obtain a cipher machine does not mean that it can be deciphered, and the cryptography is concerned with the encryption of the key rather than the encryption of the algorithm. The French know the algorithm, but it is useless not to be able to obtain the key. So the French despaired!

But after all, this opened a gap in the secret of the Enig cipher machine, and then the Germans made a mistake again, for example, the cipher machine of the three wheels needs a key composed of three letters to determine the initial position of the wheel, generally speaking, just send it once, but the Germans actually sent it twice, which made the key repeated, the first letter and the fourth letter correspond to the same plaintext! The most taboo in cryptography is repetition!

And then what. Based on this, the Poles began to narrow down the Enig cipher, narrowing the search target to about 100,000 searches. And in this way, it is possible to decipher. The Poles then deciphered the key of the cipher machine by solving the permutation matrix. As a result, from January 1933 to the outbreak of World War II in 1939, the Poles had cracked 10 German ciphers. And at this time the Germans were still in the dark!

Then the Poles imitated the Enig cipher machine and successfully connected it in series, making a deciphering machine called a bomb, which is called a bomb because when it was running. It's very noisy. It's like a bomb exploding, but it has its limitations, which is that if the other party increases the number of rotors, then this method will be extremely worky! So much so that it is impossible to fully decipher!

But fortunately, the Germans made another mistake, for example, the key should be chosen immediately, but often some people are lazy, and they just choose three consecutive letters on the keyboard and it's over. And this choice was later known to the British, which saved a lot of trouble when looking for the key! And that's not all. Then the British discovered that the Germans' telegrams had a fixed format, that is, a keyword would be repeated in a telegram! This will inevitably make it much less difficult to decipher.

Coupled with the fact that the British had more money and manpower to buy and customize bomb deciphering machines, as well as more advanced mathematical analysis. In addition, some keys and new Enig cipher machines were able to be seized from the Germans every once in a while, so the speed gradually increased in the process of deciphering the ciphers in the future, so that in the end, the Enig cipher machine had no secrets at all!

And Xu Jie, who is familiar with the entire decipherment process, naturally will not repeat the mistakes of the Germans, so Xu Jie decided to put an end to human problems first! "The production and use of all cipher machines must be strictly monitored by the secrecy organs, each cipher machine must have an exact record, the core line connection must be completely sealed, and the internal connection methods of the cipher machines of different organs cannot be the same. If a cipher machine is lost in the area, then the cipher machine with the same configuration must be returned to the factory.

"Second, the key can be sent once, but there can be a confirmation password in front of it, but it must not be repeated, and the message must not have a fixed format, even if the same type of message can not have, this is not for you to write eight strands, so you don't need to pursue the format, after the key is written for a period of time, you need to be verified by the person in charge. So that you can confirm that there is nothing identical. ”

"Third, we must give full play to the breadth and profundity of Chinese culture, so now, let's think about it, how to use the characteristics of Chinese culture to increase the difficulty of deciphering the code?" Xu Jie asked with a smile.

"Morse code corresponds to numbers, and then numbers correspond to men, you can't add classical Chinese and idioms or something, right? Or maybe some allusions? Peng Yi thought for a while and said.

"It's so difficult that few people can do both ancient Chinese and cryptography. This coding is inherently difficult. Xu Jie shook his head. As a reminder, let's say, Hanyu Pinyin. Xu Jie prompted.

"With the current English keyboard, you can type Hanyu Pinyin and then translate it into Chinese characters, but this is just one more process, and foreign countries can find two people who know Hanyu Pinyin? It's not difficult at all. Peng Yi pouted and said.

"It's different, as long as the English spelling letters can be found in alphabetical order, then they can be deciphered, for example, water is the meaning of water, but the meaning of the words represented by the same Chinese pinyin is completely different!" Su Jing's eyes lit up and she figured out something. "For example, keyi in pinyin. We can interpret it as yes, deliberately, or suspiciously!

If you put it in one sentence, then the results are even more diverse, for example, this parameter can be suspicious and this parameter is completely opposite! And this is exactly two words in the eyes of Westerners! If they can't get our pinyin and Chinese character comparison table, even if they get the key and the encryption machine and successfully decipher the pinyin message, they still can't fully understand the meaning of the message, and they can only logically infer some contents, and any failure to deduce can lead to heavy losses! Su Jing then explained.

"Yes, even with this idea, we need to give the decryptor two different keys, one is the key used to determine the position of the rotor, and the other is a comparison table between Chinese characters and pinyin. The former is immediate, and the latter we can also change the position of the Chinese characters and pinyin in the comparison table, for example, today we have the number 1 in the table to compare it is OK, and the number 2 to control it is deliberate. The number three is suspicious. Tomorrow we may be out of order, and we can add garbled text to the telegram to destroy the logic of the telegram, so that it will be very difficult for the other party to make inferences based on logic. Xu Jie added.

"Boss, you're a genius, but it's a lot of a hassle. I'm afraid that the people in the Ministry of Intelligence and Telecommunications are busy again. Peng Yi said.

"In addition, we can't just think about keeping our own secrets, we also need the intelligence department to be able to grasp the dynamics of the other party, we need more professionals and mathematicians, and even the top masters of crossword puzzles to join us in the work of deciphering and decoding intelligence. Moreover, all the confidentiality clauses I mentioned must be strictly implemented in the process of R&D, production and use of encryption machines. Xu Jie emphasized again.

"Does this mean that my group and I have lost our personal freedom at this very moment? To live under the supervision of the intelligence services at all times? Su Jing said with some dissatisfaction.

"Freedom is always relative, sometimes it's just that you don't notice that others are monitoring your movements, foreigners are not stupid, Ms. Su Jing, especially you, what you did in Nanyang back then has attracted the attention of the Dutch authorities, and of course, it has also attracted our attention. Your father advised you to come here probably because your safety in the South Seas could no longer be guaranteed, and the discovery of your invention was a complete accident. Peng Yi said with some pride, his father Peng Haifeng, as the leader of the Chinese descent in Nanyang, is naturally known as the hand and eye in the Chinese society in Nanyang. And for this person who has made outstanding contributions to the Chinese resistance, it is natural to be very concerned.

"Do you think that as soon as you come to the War Department you will be received by a lieutenant general, is it because of luck? I have a lot to deal with. When we found out that you had not only made an important contribution to Nanyang's operations, but also designed this encryption machine, we have sorted out the various forces that are tracking you. For example, a few Dutchmen who died inexplicably in Surabaya or something. If you do such a thing, and you don't have any means or experience in counter-reconnaissance, it's simply impossible not to be followed or watched by others. "Now Peng Yi is very proud, extremely proud, it can be said that he completely exudes the depression in his heart, if he wants to write, Peng Yi can't do it, but if he wants to talk about martial arts, whether it is a fight or a special operation or a large army fight, Peng Yi is quite experienced!

"Since this is the case, the road is taken by itself, so accept it. It seems that sometimes it is not a good thing to know the truth of things. Su Jing said with some resignation.

Yesterday's subscription was only half of the day before yesterday——! In the midst of tragedy. (To be continued......)