"How can I help? Is this method needed? If you want it, just use it. ”

Xu Chuan tried his best to suppress his emotions, pretending to be a high school student who heard the news for the first time and replied with surprise and some doubts.

He didn't expect that what should have appeared after the IMO actually appeared in advance.

Now that I think about it, the training time of this national set has been inexplicably extended by ten days, I am afraid it is because of this.

Moreover, those university knowledge points in the function classroom should also be prepared for these geniuses, and the country hopes to focus on cultivating a group of mathematicians in this area.

"We really need your help, this mathematical method of simplifying the Dirichlet function is important, and we need you to explain the key to it."

"Also, if you can, it's best to come with me to the Information Security Division, where dozens of math geniuses and math professors have gathered to decipher the encrypted messages, and they need this method as well."

"After all, before the mathematical model is established, this method can greatly simplify the difficulty of deciphering the encrypted information of the Dirichlet function."

"Or, can you join the Information Security Division?"

Zhang Weiping looked at Xu Chuan and asked.

"Can I take a look at those topics first?"

Xu Chuan didn't answer the question directly, and pointed to the black box in the corner and asked.

He had noticed that there was a thick stack of paper cards in the box, which should have been the kind of questions he had just done, but the types might be different.

Although he knew about information security before he was reborn, he hadn't read these topics, so he was still quite curious.

Zhang Weiping nodded, walked over and opened the black box with the key again, took out a stack of paper cards from it, and handed it to Xu Chuan.

These cards have already been deciphered, and they are in the past, so there is nothing wrong with showing them to him.

Xu Chuan took the paper card and glanced at the number.

The paper used for this paper card is much thicker than ordinary paper, according to the thickness of 0.05 mm of a paper card, there are about 40 sheets in this stack in his hand.

Just like the problem he just did was a Dirichlet function + base conversion mixture, on these paper cards, each paper card has a different problem, and there are a lot of mathematical problems mixed together.

Hash function + hash transcoding......

New Elliptic Curve Algorithm ECC+ Symmetry Function ......

RC2/RC4 symmetry algorithm + single compression function......

......

"Is this all accumulated in the past?"

Xu Chuan asked as he flipped through the paper card in his hand.

Almost every problem on the cardboard is a mixture of at least two or more types of mathematical problems, and the problems are intricately intertwined, and each problem is very difficult to solve.

"Well, this is only a part, it has been selected, and the difficulty is average, and there are some more difficult ones on the side of the Information Security Division."

Zhang Weiping replied: "At present, we intercept dozens of such encrypted messages every day, but most of them are useless data after being deciphered, and useful information only occupies a very small part of them. ”

"But often there is a lot of useless information mixed with a useful one, and no one knows which one is useful until it is deciphered."

"Manual decipherment is too labor-intensive and energy-intensive, so only modeling is the only way, and the amount of computing required by computers is far beyond that of humans, which can help us decipher encrypted messages in time and catch those people."

Flipping through the paper card in his hand, Xu Chuan handed it back and said, "Although I don't know how your modeling work is going now. ”

"But I have a feeling that your current approach to modeling may be wrong."

"How?"

Zhang Weiping frowned, and asked in some surprise, if it weren't for the mathematical ability of the student in front of him who had really conquered him, he would probably turn around and leave.

The establishment of a mathematical model to decipher the encrypted information of Area 1 is the consensus of all members of the Mathematical Society and the Information Security Division.

It is ridiculous for a senior in high school to overturn this view.

Xu Chuan thought for a while, and then said, "Actually, you can't say wrong. ”

"I don't know much about programs and information encryption, but I still know a little bit about mathematics and mathematical modeling."

"From the paper card just now, I saw a completely different encryption method."

"If I'm not mistaken, what you're doing is to make a mathematical model of every method that has come out so far, and then use that mathematical model to solve the encrypted information, right?"

Zhang Weiping looked at Xu Chuan dumbfounded and asked, "How do you know?" ”

"It's so simple that it's easy to deduce."

Xu Chuan shrugged his shoulders and continued, "First of all, the simplified method of solving the Dirichlet function will be helpful for your modeling. ”

"But in fact, after simplifying the Dirichlet function modeling, it can only decipher the encrypted information related to the Dirichlet function."

"If your approach is to find the mathematical laws behind these encryption methods, and then make mathematical models for the mathematical laws, you don't need my method."

"So I'm guessing that you should be trying to model these encrypted messages that have been deciphered, and then find the mathematical scale behind them based on these digital models, or rather, use these digital models to decipher the other party's encrypted messages."

Zhang Weiping looked at Xu Chuan in a daze, and couldn't help but swallow his saliva, what kind of monster is this?

A few simple sentences can make their guesswork clear.

Is there really such a terrifying genius in this world?

Xu Chuan ignored Zhang Weiping, and then analyzed: "In addition, I also speculate that these encryption methods may be abandoned and no longer used every once in a while, or they will be used again after a long time, which can be seen from the problems on the paper card. ”

"The reason I say your modeling approach is problematic is because the variations of functions and algorithms are almost endless."

"Translation, transformation, contraction, rotation, symmetry, asymmetry, as long as you change a little, it is almost a completely new function, which you know better than me, Mr. Zhang."

"If you want to model all the changes, it's impossible, not even if you gather mathematicians from all over the country."

"The most straightforward solution is to find the most basic mathematical rules used after these encrypted messages, and then model them according to them."

"Like now, how many encryption functions and algorithms are sent by the other party, you can build a few models, and I personally feel that this method is really not very useful."

"Maybe if you build more digital models, you can indeed find a trace of hidden mathematical laws in them, but I'm afraid it will take a year or two to pile up before you can do it."

Xu Chuan shook his head and said, he probably knew why he waited until two years later for this matter to be resolved.

It is estimated that this stupid method was adopted, and the quantitative change was piled up to the qualitative change, and the problem was completely solved.

.......