Without clearing the table or going to have breakfast, Xu Chuan threw himself on the bed after washing his face. In less than a minute, soft snoring sounded in the room.
Normally, he sleeps quietly and doesn't snore, but he was really tired yesterday.
The brain is running at high speed all day long, which consumes a huge amount of energy. The physical energy consumed by mental activities is not worse than that of physical work, or even better.
This time, Xu Chuan slept until about two o'clock in the afternoon, then woke up slowly.
After taking a shower to clear my head, I bumped into Zhang Weiping as soon as I went downstairs to eat.
"Hey, you're here. Where have you been this morning? I'm looking for you. I couldn't get through to you even if I called you just now."
Zhang Weiping called to Xu Chuan and was a little curious about where he had been in the past two days.
Xu Chuan thought he missed a call while taking a shower. He took out his phone and took a look, only to find that the screen of the phone he had kept in his pocket had gone black.
He smiled awkwardly, shook the cell phone with a black screen, and said: "I have been in the room all the time. I stayed up for a while last night looking at those problems. I got up a little late today. The reason why the call can't be connected is because the phone is not working." The battery ran out and I forgot to charge it.”
"You, don't work too hard, you still have to pay attention to your health, the future is still long."
Zhang Weiping shook his head and advised, other students need to be pushed to study, but this one needs to be persuaded not to work too hard.
Xu Chuan nodded: "Well, I will pay attention. Teacher, do you have any business with me?"
"Oh, yes, I almost forgot."
Zhang Weiping suddenly came to his senses and continued: "We have basically read the information on solving the Dirichlet function using the simplified method. You go to bed early tonight. We will have a small meeting in the mathematics room tomorrow. We will discuss some issues and ideas then. one time."
"Well, okay, what time will it be tomorrow?" Xu Chuan responded and asked the time.
"This depends on tomorrow's work schedule. If there is a lot of information that needs to be deciphered tomorrow, it may be pushed back."
"Then teacher, just contact me then. I'll be in my room."
"Okay, remember to charge your phone." Zhang Weiping smiled and patted Xu Chuan on the shoulder.
...
After finding some food and filling his stomach, Xu Chuan quickly returned to his room and continued the unfinished work in the morning.
The meeting tomorrow is a good opportunity for him, and he can put forward some ideas and methods at the meeting.
But time is tight. He needs to figure out the mathematical rules behind this information war before tomorrow's meeting.
Not to say that you have a complete understanding, but at least you have to be able to understand the general direction.
After all, if he doesn't figure it out himself, how can he give hints to others?
Fortunately, the whole night last night was not in vain. Now that the thread has been found, the remaining work can be continued after the thread is sorted out.
Stripping of hexadecimal transcoding, composite functions and single functions jointly define the function domain, the participation of sets to determine values, the hash function to change the input string into a fixed-length output string, and the determination of the types of composite functions and basic functions.. ....
After having enough inspiration, Xu Chuan found out the secrets behind these mathematical problems one by one.
Basic, but complex, it is the best explanation of the mathematical laws behind these encrypted messages.
In the evening, Xu Chuan put down the signature pen in his hand, stared at the manuscript paper on the table and frowned.
By now, he has almost figured out the mathematical laws behind these encrypted messages, but there is still a very critical point that he has not found out.
That is how to determine which functions and set definitions to use every time the encryption algorithm of these encrypted messages is changed.
If this problem is not solved, it will still be difficult to establish a comprehensive mathematical model to decipher these encrypted messages in a timely manner.
Xu Chuan did not believe that the first area would use completely random functions and sets to perform encrypted combinations, because this was impossible.
The other party must have a function library in hand, and then generate function questions through calling and combination and then compile the encrypted message.
But the huge functions and collections determine that if it is applied immediately, even if the intelligence personnel in District 9 have deciphering equipment, it will take a long time to solve it, or it will be impossible to solve it.
Because if there is no pattern, every time it is applied and decrypted randomly, the calculation difficulty and the amount of calculation required will increase exponentially.
It only requires two-digit function application to kill any home computer.
If the function application grows to three digits, it will take a long time for a supercomputer to solve it if there is a digital model.
Unless these spies use supercomputers as deciphering equipment, this is nonsense. How can ordinary computers have so much computing power to perform calculations?
So this is obviously impossible.
Xu Chuan didn't believe that the intelligence personnel would know what kind of function the deciphered function was, and then use digital models to solve it after confirming it.
Not to mention the spies, even he himself didn't dare to say that he knew all the functions.
With a slight twist, this thing is a brand new kind of person that everyone can recognize, and that person is 100% the top mathematician in a country.
It would be even more outrageous for such talents to be sent as espionage agents, even if the President of District 1 is replaced by a dog.
Therefore, there must be embedded patterns in the original ciphertext or the initially cracked plaintext.
...
Thinking about it, Xu Chuan turned his attention to the original cipher text and the deciphered plain text.
Still preliminary sorting the information in chronological order, and then attaching the function questions and answers below to look for clues.
But the huge and messy original ciphertext made him instantly give up the idea of reading the original ciphertext first, and turned his attention to the initially deciphered plaintext.
This time, it didn't take long. After reading several clear text messages and corresponding function questions, Xu Chuan's eyes brightened. He probably already knew what methods the other party used.
However, in order to make sure that the thoughts in his mind were correct, he still chose to continue reading the remaining information.
.......
