Yu Hua took the black document bag from Hua Luogeng, opened the seal on the surface, and took out the Japanese original plain text information contained in it. These documents belonged to the latest plain text communications of the Japanese foreign affairs department and the garrison army, all of which were eavesdropped by the Blue Clothes Society.
Pick up the first page at random, and the contents recorded on it are all in English letters.
Japan's original plaintext is not Japanese characters, but English alphabetical structures. The Hill cipher is composed of a twenty-six-digit encryption matrix. Due to too many Chinese characters and Japanese characters, it is not suitable for the Hill cipher. The Japanese follow the international mainstream practice. The Hill cipher algorithm structure, which uses English letters and numbers to relate to each other, does not specifically compile a set of hexadecimal Japanese characters.
From the surface of the first piece of original plain text, there is no regularity in the arrangement of the entire string of English letters. It is stiff and abstract, giving people a feeling of random scribbling. Yu Hua took a first look and immediately thought of countless English letters. Taobao accounts are like this.
After reading the first piece of original plain text information, Yu Hua carefully wrote down all the contents, with a natural look on his face, and was not in a hurry. Then he turned to the second piece and continued reading. According to the usage rules and habits of human linguistics, even if there is no rule, As long as words are related to people, there will definitely be patterns.
The first rule of cryptography: People will always make fatal mistakes - habits.
Seeing this, Hua Luogeng did not rush him, but waited quietly with a smile on his face.
About ten minutes later.
Yu Hua put down the latest piece of original plain text data. He had already read about one-third of the original plain text data. He closed his eyes. A large amount of Japanese original plain text data had accumulated in his mind. Strings of English characters were suspended in the air, densely packed. The number reached tens of thousands. In the next second, his computer-like brain was operating at full capacity. Yu Hua first used the most effective and direct frequency analysis attack method to extract the frequency of occurrence of letters and letter combinations.
After a few seconds, a set of ciphertext combinations appeared - a, abb, abbf, ath.
In this set of ciphertext combinations, the ciphertext letters and letter combinations appear most frequently, reaching 200, 89, 76, and 23 times respectively. After obtaining the first set of ciphertext combinations, Yu Hua continued to use the frequency analysis attack method. A series of ciphertext combinations are obtained.
Seeing Yu Hua close his eyes, Hua Luogeng knew that his student, whose mental arithmetic ability was extremely terrifying, had already begun frequency analysis and deciphering, and there was a look of anticipation in his eyes.
Among other things, this student of his is undoubtedly the best in the country in saving manuscript paper.
Even Hua Luogeng, who was famous for his mental arithmetic at Cambridge University, couldn't do mental arithmetic in front of Yu Hua.
In his mind, groups of ciphertext combinations continued to appear. Until the frequency analysis was completed, Yu Hua obtained a total of 438 groups of ciphertext combinations. Then he conducted reverse analysis based on the encryption algorithm principle of Hill cipher. Through the calculation of calculus, Thinking, establish an approximate matrix, and continuously analyze 438 sets of ciphertext combinations in reverse.
The entire analysis process was extremely energy-consuming. Yu Hua had no idea or any tricks. When the code deciphering reached the analysis stage, he could only go head-on. There was no other way.
Historically, in order to crack the German Enigma machine, the United Kingdom mobilized the efforts of the whole country, gathered many mathematicians and related personnel, and assembled a code-breaking team of more than 10,000 people to carry out code-breaking work 24 hours a day, 24 hours a day. Give resources to resources and give them what you ask for. Finally, under the leadership of Turing, they found the fatal weakness of the German army and were able to crack the Enigma machine, which was said to be impossible to crack.
But in the analysis process of cracking passwords, there is no so-called shortcut. Either you have to finish counting these numbers, or you don't even want to get the information.
Fortunately, Yu Hua has a brain comparable to a computer, and his computing power is comparable to an eighth-generation Core i5 CPU.
An hour later.
"Huh..." Yu Hua suddenly exhaled a breath of turbid air, his whole face turned pale, he was dizzy, and he was shaking as if he had been hit by a heavy hammer on the back of his head.
"Xiaohua, are you okay?" Seeing Yu Hua's appearance, Hua Luogeng was also a little startled. Seeing this state for the first time, he quickly asked with concern.
Yu Hua shook his head repeatedly, feeling a little nauseous. He took a deep breath, cheered up, and said quickly: "Professor, I'm fine. This is the alphabetical order of the ciphertext I am trying to decipher. Currently, I only find the numbers corresponding to the 4 letters. A corresponds to =9, b corresponds to =2, f=3, h=1.”
"abfh, very good. I have deciphered 6 letters during this period, and they are not the same as the four letters you deciphered. With the 4 new letters you deciphered, we have a total of ten letters. Now we can establish an approximation If you put ten letters into the matrix mathematical model... you can decipher some of the original plaintext words."
Hua Luogeng was pleasantly surprised when he heard the combination of four letters and numbers given by Yu Hua. He picked up the pencil in his right hand and wrote it down immediately. Then he performed mental arithmetic in his mind and quickly gave the calculation result, with a hint of excitement in his words.
surprise.
A real surprise.
He couldn't help but Hua Luogeng was not surprised. He had no choice. For nearly a month, Hua Luogeng had been worried and troubled every day about deciphering the Japanese cipher text. It was not that he had no ideas, but that he did not have enough manpower. In more than 20 days, he only deciphered Six letters.
Today, after Yu Hua came into contact with the work of deciphering Japanese cipher text for the first time, he immediately gave him a big surprise.
Don't underestimate these four letters. The four letters deciphered by Yu Hua are all new letters and do not overlap with the six letters deciphered by Hua Luogeng before.
In other words, with the number of deciphered letters reaching ten, they have now begun to master the ability to decipher some original plaintext words. Presumably, the previous situation was a breakthrough.
After hearing this, Yu Hua smiled reluctantly and said nothing. His face became paler and his whole body felt more and more dizzy. He couldn't help but hold the table with his right hand to support his body.
"Xiaohua, if you crack 2-4 letters every day, it will only take about 8-4 days for us to complete the first goal."
Hua Luogeng raised his head, suppressed the excitement in his heart, and said: "In the near future, we may be able to decrypt the cipher text simultaneously in a single time."
In Yu Hua, Hua Luogeng saw the hope of simultaneous deciphering, which is the supreme pursuit in the field of code deciphering.
What is simultaneous deciphering?
The sender sends a communication message to the recipient, and the eavesdropper, as a third party, and the recipient simultaneously obtain and translate the content of the information sent by the other party.
In layman's terms, the Japanese garrison sent a mobilization order to a certain regiment. This order was obtained and translated by both the own side and the regiment at the same time. The situation would evolve into a situation where the regiment did not know that the cipher text had been leaked. Immediately mobilize the troops and set off. If you get the communication order, you can choose to escape, ambush on the road, or even sneak attack the regiment station.
What is this called?
One-way information transparency.
What is the advantage in me? The party with one-way information transparency is called the advantage in me!
This situation is undoubtedly great news for the country and the army.
"Teacher, professor, student..." Yu Hua opened his mouth and wanted to speak, but his voice was as weak as a mosquito. After two seconds, he still hadn't finished speaking. The dizziness was so strong that he couldn't hold it in anymore. , his whole vision suddenly went dark, he lost consciousness, and immediately fell to the table.
"Bang!" Immediately afterwards, Yu Hua's head came into close contact with the table, and there was a loud and short impact sound.
"Xiaohua!"
…
"Come on, old guys, let's go, let's watch me eat a piece of cake, and everyone will give me a reward."
"Thank you for the gift, Brother No. 1, thank you."
"Hey, pay back the skin, just pay back the skin-turning water."
“In the new season, go for it, go for it, if you don’t rank first in the national server, you will be eliminated.”
Yu Hua looked around blankly, and the sounds of various live broadcast rooms kept coming to his ears. This was his computer, surrounded by a bedroom with simple furnishings, a computer desk, covered with stickers of various military equipment, and A bookcase, the scene in front of him all shows that this is his home.
what happened?
I'm home?
