The afternoon class is number theory and password, which is a professional elective course.

However, generally speaking, students majoring in applied mathematics will choose this course. After all, there are 48 theoretical courses and 4 credits, which is extremely cost-effective.

As the name suggests, this course talks about the application of number theory in cryptographic systems, and belongs to a branch of applied mathematics.

It's just undergraduate content, so it's not very in-depth. It basically talks about the history of the development of elementary number theory and cryptographic informatics. In fact, it's very interesting to learn it. Even if you can play it, you can come up with a story.

The afternoon class time of Jiangda is 2:05.

Ning Wei was already ten minutes late when he arrived at the classroom.

What's even more annoying is that the back door is locked.

Ning Wei was standing at the front door and hesitating, thinking about whether to skip class or not, but by chance, the teacher on the podium called his name.

"Ning Wei, let's answer this question."

Ning Wei, who was standing outside the door, hesitated for two seconds. Is it such a coincidence?

"Hmm? Ning Wei didn't come?"

Annoying!

"Professor, I'm here." Ning Wei stood at the door with a blushing face, in return for a burst of laughter from the podium.

"Um?"

Professor Chen on the podium pushed his glasses, looked at Ning Wei, who was standing at the door holding a laptop bag. He was not angry, but was happy: "Huh? You are Ning Xueshen? By the way, have you calculated that I will order you today? Come and cooperate with me?"

"Professor report, Director Li asked me to send him some materials, so he was late."

"Oh, okay, come in and take a look at this problem by the way, how to solve it?"

As the classmates laughed, they walked into the classroom, scanned the contents of the PPT on the eye projector, and the elliptic curve was encrypted.

Soon, the basic operation rules of the elliptic curve were sorted out in his mind, addition, double operation, positive and negative inverse, infinite distance, finite domain...

Then the problem-solving process and answers appear naturally in your mind like breathing.

"Report professor, because the elliptic curve y2=x3+ ax+b on the finite domain GF(p), if P(Xp, Yp), Q(Xq, Yq), and P≠-Q, then R(Xr,Yr)=P+Q should be determined by the following rules..."

"Wait, how can I remember you? Come to the podium and write on the blackboard." Professor Chen stopped Ning Wei directly.

Helplessly, Ning Wei put the notebook on the lectern, picked up the electronic pen and started writing on the blackboard.

“Xr =(λ2- Xp - Xq) mod p

Yr =(λ(Xp - Xr)- Yp) mod p

where λ=(Yq - Yp)/(Xq - Xp) mod p(if P≠Q), λ=(3Xp2+ a)/2Yp mod p(if P=Q)..."

Soon, after several steps, it was concluded that 3G is the point (3,13).

"Well, I have a good understanding and my thinking is very clear. Oh, the teacher is really honored. It seems that I have learned this book myself before. No wonder I dare to be late. Okay, go find a seat to sit down." Professor Chen waved.

I would rather get an amnesty than get an amnesty, pick up my notebook and go to the back row.

Generally speaking, even if he doesn't come, the brothers in the dormitory will help him take a good seat.

Sure enough, as soon as he arrived at the back row, he saw Luo Xiang waving at him. Ning Wei immediately got over. He had just finished it and had no time to take a breath and told several people the good news that they were targeted, the professor on the stage spoke again.

"Ning Wei, why are you going so far? Forget it, I won't bother with you. Tell you, one of the topics I am studying is the fuzzy extension method of pseudo-Bolean function N-person countermeasures. It's very interesting. If you are interested, call me back and call me. I'll help you write a report to apply for a direct job quota."

"Wow……"

There was a burst of envy, jealousy and hatred in the classroom...

Ning Wei was stunned, but obviously Professor Chen didn't plan to wait for his response. He operated the computer twice, skipped the question just now, and turned to the previous content: "Okay, we'll start to teach the class according to the routine. Ning Wei's elliptic curve encryption content just now was just talked about in the last few classes, and it increased the difficulty. So the order is wrong. Forget it, just let's take a look, it doesn't matter if you don't understand. What we are going to talk about today is the quality detection algorithm."

"I don't have to listen anymore, but I suggest that others should listen carefully. Because I received news before class, many of our professors think that your students are of very high quality, and they can be said to be hidden and hiding. It's no exaggeration to say that several professors think that you may be the best class we have ever taught!"

"So the overall difficulty of the final exam this year will be higher than in previous years, and it will probably be closer to the base class. Other professors have raised the difficulty. It is not good if I don't give you some difficulties. It seems that I am not very sociable and even more like I look down on you, right?"

"wrong!"

At first hearing the bad news, a group of poor children under the podium answered in an orderly manner, and then quickly became confused: "Professor Chen, please, you look down on us, right?"

"That's right, what kind of words are these? Professors, don't play like this!"

"Not everyone is as perverted as Ning Wei!"

"Professor Chen, we are just children! Normal children!"

"Ningwei has only one, but there are many ordinary people! It will kill people if it is more difficult!"

It's really wailing all over the world...

Especially Xu Ruixuan, who was beside Ning Wei, shouting the most with Luo Xiang, and Liu Cong complained a lot. Ning Wei realized that Liu Cong went out early in the morning to get a haircut, and changed into a short hair, and looked much more energetic.

Professor Chen stood on the podium and smiled without saying a word until the sound finally became smaller. Then he raised his hand and suppressed everyone's enthusiasm. An aunt-like smile appeared on his face: "How could that be? We have obtained secret information. You children usually say that it is difficult and that is difficult in class. The exam should be simple. The private study of self-conservation functions, Howe dual conjecture, matrix coefficient, and Ramsey's second dyeing is not just Ning Wei!"

"So this year the difficulty will definitely be increased, and the graduation thesis will also put higher requirements on everyone! Okay, stop making trouble, now I'm going to formally start class! Before learning the primitive detection algorithm, we must first understand what primitive detection is. As the name implies, it means to determine whether an integer is a prime number, which is called primitive detection..."

Professor Chen started formal lectures, but Ning Wei was stunned.

The difficult problems Professor Chen just mentioned were very familiar.

Of course, it is difficult to be familiar with it.

The article that the three of them prepared together was read at least ten times. Although they searched for reference books everywhere, they naturally remembered it after reading it more than ten times.

Of course, there are more than just a few difficult problems in mathematics, but these difficult problems happened to be chosen by the three.

Just so, it's a little worse than that kind of global problem...

so……

"It's paralyzing! Are the professors so idle? Don't they want to do research? They still have time to visit Zhihu? How is that possible!" Xu Ruixuan, the author of the article, sighed in a daze.

Ning Wei glanced at Liu Cong, who was also melancholy, and thought about it, but still didn't say anything.

Yes, professors probably won’t have that time to follow Zhihu, but who makes you like offering treasures so much?

When Professor Chen finished speaking on the podium, many people twisted their heads to the back row and focused on the other three people in 302...

Obviously, among the classmates, many people have seen Xu Ruixuan's masterpiece and are deeply impressed.
Chapter completed!