"Hello, Professor Quillen, Professor Slavic, Karachi and other professors have arrived!" Just as Junxin and Professor Quillen were chatting happily, Miss Mandani, Professor Quiron's teaching assistant, knocked on the door and walked into Professor Quillen's room.

"Oh, invite them in!" Professor Quillen happily stood up and said to Miss Mandani.

Miss Mandani walked out in response, and Professor Quelen and Junxin also consciously stopped talking and looked at the door, at this time, a few mathematicians who had met at the Princeton Mathematical Exchange walked in talking and laughing, it was Professor Slav and Professor Karachi and others that Miss Mandani said.

"Hello, dear Slavic professor, Karachi professor!" After seeing them come in, Junxin hurriedly got up and looked at the two professors and said.

"Oh, it's a great honor to meet you, dear gentleman, you're even more handsome than you were two months ago!" Professor Slavic said with a smile. Professor Slavic was born in a Slavic nation, and his real name is naturally not Slavic, but because his father was a staff member of the original Tsarist Russian Embassy in the United States, and later stayed in the United States after the establishment of the Soviet Union and became an American citizen, the meaning of the Slavic name is to be born in the Slavic people. Professor Slavo's main research is biased towards mathematical control and mathematical probability analysis, and he is also a well-known mathematician in the world, with a cheerful personality and a penchant for jokes, so he is relatively famous in the industry.

"Dear Jun, it's an honor to meet you!" Compared with the inattention of the Slavic professor, Professor Karachi is a very gentleman, a mathematician from an aristocratic British family who specializes in mathematical physics and engineering mathematics applications, and is half of Junxin's peers. He has the unique British aristocratic scholarly bearing of the late nineteenth and early twentieth centuries.

"I'm so happy to meet a few professors again!" After shaking hands with several professors one by one, Junxin sat down again and said with a smile.

"Planning to spend a few days at Mit? I think I can be your guide, I've been in Massachusetts for decades! Professor Slavic said with a smile.

"I'm going to go back before Christmas, today is the 21st, and tomorrow I've promised Professor Yau to have a lecture at Harvard, and the day after tomorrow there's a basketball game at Mit, and I'm the assistant coach of the Princeton basketball team. On the evening of the 23rd and the 24th, I was free all day, and at noon on Christmas Day, I had promised Professor Yau Chengtong to come to his house for lunch, and I would go back to Princeton in the afternoon! "For his own time, Junxin has already arranged it, so he naturally comes as soon as he opens his mouth.

"Oh? Jun, you still have an academic lecture at Harvard? Is it about the four-dimensional Poincaré conjecture? Professor Quillen asked with interest, although he was not an expert in the study of geometric topology, but an expert in topological algebra, and quickly thought of what Junxin might say.

"Yes, the four-dimensional Poincaré conjecture has been published for half a month, and my colleagues in the industry have almost completely digested my paper, and it is indeed time to give an academic lecture or something, to answer some questions and problems in the paper, you know, I am very short of time now, and I have almost no spare time to write to those mathematicians who wrote to me, this form of lecture report focusing on explaining and answering questions is the best and most time-saving method!" Jun Xin shook his head and said a little helplessly. In the past, the Internet and e-mail made it easy to communicate with scholars from all over the world, but now that these have not yet been created, communication with each other has become particularly time-consuming.

"Then you can't favor one over the other!" Professor Quillen smiled and said, "On behalf of Mit, I also invited you to give a math report, what do you think?" ”

"Professor, you're a little embarrassed about me!" Jun Xin scratched his head and said, "In fact, you don't know that Mit's bias towards engineering education is not my research direction in the first place, and there is no problem in explaining it, but topological geometry is a bit too abstract and very difficult to use, and the results of the four-dimensional Poincaré conjecture should not have much impact on Mit, right?" ”

The Poincaré conjecture does have a high influence in science, but in fact, it does not have much influence in engineering, or it is not useful at all in engineering in this era, but the greatest use is in theoretical research, so Junxin was not prepared to give a lecture on Poincaré conjecture at Mit when he came to Mit.

"Let's talk about the Poincaré conjecture!" Professor Quillen smiled and said, "I know that you actually have research in many aspects of mathematics, even in the application of mathematics you have your own opinion, but we in Massachusetts also have our own purely theoretical research, not just the School of Engineering!" ”

Jun Xin looked at Professor Quillen with serious eyes, and after seeing him nod slightly towards himself, he immediately understood what Professor Quillen was thinking, and after sighing secretly in his heart, he agreed by the way. In fact, he was prepared to go to Massachusetts to give a report, but not to his latest research find, the four-dimensional Poincaré conjecture, but to prepare an algorithmic problem of electronic computers, which was proposed by three electronic computer scientists at the Massachusetts Institute of Technology in 1977 about the vulnerability of the RSA public key encryption algorithm for information transmission, and the purpose was also to attract the attention of Professor Alan Paley, so as to create an opportunity to talk to Professor Paley alone, which now seems to be unworkable.

"Thank you, I will arrange for the school to prepare other things for you, and the time will be temporarily arranged on the evening of the 23rd, what do you think?" Professor Quillen asked.

Junxin nodded and said, "I don't have any problem with the time, you just avoid my working hours!" ”

Professor Quillen laughed: "It seems that you have already prepared the report, but I disturbed your preparation, can you tell me what the report you prepared in Massachusetts was?" ”

Junxin shook his head and said, "It's not something very special, it's a computational proof of some vulnerabilities in the RSA algorithm named after the initials of the three of your school, together with three staff members of your school, Ronald Rivest, Adi Shamir, and Leonard Adleman, in 1977. ”

"Oh? When did you first get involved in computers? The Slavic professor, who had been listening quietly, suddenly asked.

"The last time I went to the University of Pennsylvania, Professor Porter introduced ENICA and EVDCA to me, and I had some interest in electronic computers, and after I came back, I completed the four-dimensional Poincaré conjecture and studied a little bit of computer algorithm problems, and RSA was my research result during this time!" Junxin explained.