"Lao Liu, are you there?" Coming to the door of the office in three steps and two jumps, Xu Wenxin knocked on the door lightly and asked.

"What's the old Liu, the old Liu, the two of us are just like the forty or fifty-year-old old man." Liu Wenyu frowned and pushed open the door, "What's the matter, excited like this?" ”

"Hey, hey, hey," I saw her look like a nymphomaniac, and she jumped into his office and said, "Yes, after Team Yan leaves, this will be your place." ”

"It's just temporary, if it weren't for the fact that the case was too bad this time, and the original leader of our police station was transferred because of the ineffective handling of the '9.12 murder case', how could I be temporarily pushed out of the town?" Scratching his head, he said with a wry smile: "Don't be sarcastic about me, these recent things have made my head blow up." ”

"If it weren't for Mr. Wen's pseudonym 'W' coming here to assist us in our investigation, maybe you would have slammed into the wall and died by now!" Xu Wenxin covered her mouth and chuckled: "You can be content, the office has air conditioning and water dispensers, and the ventilation is very good, it is not too happy to be able to sit here and work." ”

"It's going to be winter soon, so you turn on the air conditioner." After muttering a few words, Liu Wenyu asked, "What's wrong, what's the progress?" ”

"Teacher Wen is really amazing, I just received the news this morning, and in less than two hours, I sent the password over, and it also came with a bunch of places to explain in various places." Putting a dozen materials on his desk, Xu Wenxin covered her mouth and chuckled: "It's really the first time I've heard that there is knowledge about classical ciphers, and there is such an ingenious thing in this world, it's really a matter of knowledge." ”

"The Belaso code? It's kind of interesting. Liu Wenyu nodded, and then picked up another piece of paper placed in the brown paper belt, "This ...... What kind of demons and monsters? ”

GAAFXFXDAGDXDFXFFAAAAFDFGAGFXGGAAFXAFDADAAXFAFDDAXGGADXFDXAFAXFADXAFDGAGXDAFAFXDAGADFFDDAXAGGDXDDFXFAFDXDAGAFAAAGFGDAXGFGADFFXADFX

"Ah, this, this is the next layer of encryption that Mr. Wen said." Xu Wenxin casually picked up one of the materials, and then explained: "This kind of password, Teacher Wen said that it is called the Polybios Phalanx Cipher. ”

"Polybius phalanx, is a kind of chessboard cipher, is the use of Polybios phalanx for encryption of the cryptographic method, produced in Greece in the second century B.C., according to legend is the world's earliest cipher. To put it simply, it is to arrange the letters and express them in the form of coordinates. Letters are ciphertext, and plaintext is the coordinates of letters. Gently reading out the information on the data, Liu Wenyu fell into deep thought, "Since you already know this encryption method, why don't you just decipher it?" That's obviously a 26-word alphabet, and there's no key to it. ”

"It's been broken, but Mr. Wen said that the deciphered content doesn't look like another layer of encrypted passwords," Xu Wenxin took out a small note, "Although I can't see anything, Mr. Wen's original words are, 'It's like a neat ball of threads that were originally grouped into an untidy ball of threads, which is almost impossible for ordinary people to see, but after being experienced, you can immediately feel that something is wrong'." ”

"DLPKQWMPCAQRDTUDLEHFAPLGVTFPWLVCWLRQKLLKQFNGVQIKMPLWBDCAOIVODMXFX......" scratched his hair vigorously, and he sighed slowly, "It's a shame to say, in my opinion, all of them are like gibberish." ”

"Maybe that's the difference between the average person and a cryptographer, or maybe it's just that we're alone." Xu Wenxin nodded, "And I also thought in private, since this murderer is bold enough to give the police a puzzle, then this arrogance must have a certain amount of knowledge as a scaffold, presumably the murderer will not leave such a low-level puzzle." ”

"Yes, it's reasonable, maybe staying with Teacher Wen for a while can really help people become smarter." Liu Wenyu couldn't help laughing, "So about this matter, did Mr. Wen say anything else?" ”

"Of course, I'll explain it to you." Xu Wenxin sat on his desk with a big grin, opened a volume of materials, and said, "Let me tell you about Mr. Wen's explanation of another encryption method first!" ”

"In 1918, towards the end of World War I, the French army intercepted a German telegram, all the words in the message were spelled by the five letters A, D, F, G, and X, hence the name ADFGX cipher. Invented in March 1918 by German Colonel Fritz Nebel, the ADFGX cipher is a double encryption scheme that combines the Polybius phalanx cipher and the displacement cipher. Closing the information, Xu Wenxin blinked mischievously, "How is it, do you understand?" ”

"No, you little ancestor, can't you say something I understand?" Scratching his head with a slight headache, Liu Wenyu said angrily: "Talk about people!" ”

"Hehehehe," Liu Wenyu's reaction obviously amused her, she cleared her throat, and she continued: "Then, I'll give you an example!" ”

"For example, I'm an officer, and I want to give an order to my subordinates, such as 'Attack at once', and then by looking up the Polybius phalanx cipher table, we can change the content to the following cipher."

Grabbing a pen in hand, she writes down a password on scratch paper: AF AD AD AF GF DX AF AD DF FX GF XF

"Next, use a shift key to encrypt. Let's say the key is 'CARGO' and write it in the first column of the new grid. Then write the ciphertext from the previous stage into the new box, one by one, like this. ”

Then she wrote another paragraph:

C A R G O

One by one

A F A D A

D A F G F

D X A F A

D D F F X

G F X F X

"Finally, the keys were reordered in 26 alphabetical order to become 'ACGOR', and finally the entire column of information under each letter was copied in this order to form a new ciphertext, and so it became."

She slowly wrote down something new, and the original password became: FAXDF ADDDG DGFFF AFAXX AFAFX

"Look, this is the whole process of encryption, if you want to decrypt it, you need to know the key used by the other party to encrypt." Helplessly spreading her hands, Xu Wenxin said: "So, in addition to being able to catch the murderer right now, I can only wait for his next prompt." ”

"In this case, there is only one way to catch the murderer." With a long sigh, Liu Wenyu shook his head helplessly, "How's the investigation?" ”

"After visiting and investigating, the only thing that these two victims have in common is that everyone in the family has an outrageously poor reputation in their own area." took out another bag of materials, Xu Wenxin said: "To be honest, the murderer was able to find two such ones, which is really amazing; And it's really rare for the reputation of these two to be like this. ”

"So, the murderer should be among those who know their reputation?" Liu Wenyu asked: "In this case, we only need to compare the range of people that the two families can contact and screen out those who meet this condition, won't the case be solved?" ”

"It's not that simple, according to Mr. Wen's words, first of all, you can't screen out such a wide range of people, let alone the 'second-level acquaintance' mentioned earlier, this kind of blurred classification, third-level or even fourth-level acquaintance, is a possible thing. What's worse is that no one specifically remembers saying these things to someone, which means you can't find anything meaningful at all. Xu Wenxin picked up a piece of information casually, "So, it's no fun~"

"So, where do those flowers come from?" Liu Wenyu was not hit, but then asked: "Did the comrades who investigated Hua before bring any exciting news?" ”

"It's a pity that this clue is also broken." Xu Wenxin said with a wry smile: "Due to the particularity of these flowers, ordinary flower shops almost do not sell them, and after identification, those flowers have only been picked recently, compared with the goods sold by flower shops in this city recently, there is no large number of transactions about these flowers." ”

"So we still don't have any evidence of a breakthrough?" With a long sigh, Liu Wenyu said a little tiredly: "...... such words?"

"Report to Team Liu!" The door of the office was suddenly pushed open, and the police officer walked in slowly and handed Liu Wenyu a brown paper bag: "Team Liu, this is your courier." ”

"I don't remember ordering a courier......" Liu Wenyu took the paper bag and just wanted to open it, but suddenly stopped the movement in his hand.

"Wait, how did you get this bag?" Exchanging glances with Xu Wenxin, he looked at the bag of things vigilantly.

"The courier was left at the door, and it was sent in by the comrade on duty." The officer looked at him quizzically.

"Immediately sent to the trace inspection department, I never ordered a courier, and the courier didn't let me sign for it!" In the next second, Liu Wenyu immediately pushed open the door of the office and walked out quickly.

………………

"Okay, thank you, Principal Du, I see." Gently putting down the phone in his hand, he looked at Wen Qingyu, who was bored sitting on the sofa and playing with Lin Yunqian's bandages, and couldn't help laughing: "If you keep playing with bandages, maybe I have to change the bandages for him again." ”

"Then I don't mind." Looking at him with a grin, Wen Qingyu spread his hands, "Anyway, it's not on me, the teacher won't beat me, right?" ”

"He won't, I will." Lin Yunqian glanced at her angrily, "Normal saline is mistakenly taken into alcohol, it's really a shame that you stinky girl thought of it, if I hadn't smelled alcohol, you would have fallen!" ”

"There's no way, when people get old, their eyes will be spent." Wen Qingyu pretended to be helpless and grimaced, "Moreover, I am still a minor, if my uncle beats me, I will sue you for the crime of abusing a minor." ”

"A stinky girl, pretty powerful."

Seeing that the two fell into an argument again, Wen Yifan looked at his watch a little helplessly.

- I vaguely remember that the last time they were quiet was two minutes ago.

"Qingyu, don't be big or small, think about those ghost ideas every day." After the two of them quieted down, Wen Yifan said: "By the way, Yunqian, I just helped you find a job, you can try it tomorrow." ”

"Huh? So fast? ”

"Haha! A certain uncle finally can't stay at home every day. ”

Hearing this, Lin Yunqian looked at Wen Yifan with a little surprise, while Wen Qingyu on the side let out a gloating laugh.

- Wouldn't I be able to devote all my time to investigating? It's not a good thing to have to take care of your work while also beware of "writer" investigations.

- Moreover, since I want to join the company, then I need to provide relevant documents about my identity, not to mention that now my ID card has been stolen, even if I get it back, I must not be able to call the police, because the "writer" can monitor the police system, which also leads to the fact that if you call the police, it is very likely to leave clues and let the "writer" follow the trail to find himself.

- In this way, if you find a job, it will do more harm than good. Sure enough, for the sake of a lie, you have to tell more lies, so that you are smart but you are mistaken by your cleverness, which leads to yourself entering an unfavorable situation.

"What kind of job, found so quickly?" After stabilizing his mood a little, Lin Yunqian asked, his brain was spinning rapidly at the moment, looking for a logical and non-abnormal way to refuse.

"It's the same job as me, going to our school as a teacher." Wen Yifan smiled slightly and explained: "Your physical strength is very good, and the sports should not be too bad, because of my relationship with the principal, he readily agreed to this proposal, and asked you to go to school tomorrow." ”

"Tomorrow...... Just go? Lin Yunqian obviously looked a little puzzled, "So fast?" Don't you even need an interview? ”

"In the words of the principal, it is to trust me and think that the people I recommend must have merit, so the interview process is omitted." Wen Yifan explained unhurriedly.

"Don't even need identification documents?"

"No, just go straight to work." Wen Yifan smiled slightly, "Oh, by the way, I also made a personal request, and the principal quickly agreed to it - you will be a physical education teacher and take a class with me." ”

"Huh?" This time it was Wen Qingyu's turn to be unhappy, "I don't want such an uncle to teach me physical education!" ”

- Don't you even need an ID card?

Doubts slowly rose in his heart, Lin Yunqian frowned slightly, and asked, "Can you easily explain, what kind of relationship do you have with the principal?" ”

- Do you see the discord? It's okay to tell him, anyway, over the years, a lot of work has been done on his life experience.

"You've found out." Wen Yifan smiled a little helplessly and said, "In fact, these days, I can also see your doubts, in fact, you have always wanted to figure out, why can I, an ordinary teacher, receive a salary of 3,000 yuan a month, be able to afford such a big villa, isn't it?" ”

"yes, but because that's your privacy issue, I didn't ask." Lin Yunqian nodded and generously acknowledged.

"You can understand that these are all family assets left to me by my parents." With a long sigh, Wen Yifan said.

"The family property left by the parents?" Faced with this answer, Lin Yunqian was obviously stunned: "What about your parents?" They died? ”

"It would be nice if it was dead, the truth is worse than guess, they are missing." Taking a deep breath, Wen Yifan said with a slight wry smile: "Just like you think, a pair of parents who left their newly adult children and tens of millions of family property mysteriously disappeared. ”

"What did the police say at the time?" Lin Yunqian frowned, "If it is a rich man of this size, it should attract the attention of the police community, and the case should not be closed hastily." ”

"In fact, the case was hastily closed." Wen Yifan slowly walked to the bookshelf and took out a newspaper, "Look, this is the situation at that time - they only left a letter and a property transfer, and the rest, nothing." ”

"After all these years, you didn't want to go over and find them?" Lin Yunqian took the newspaper and read it for a long time, but he still asked a little incredulously, "What did the police say at that time?" ”

"It's very simple, they just told me that my parents might have been killed, and they wanted me to be mentally prepared," Wen Yifan said slowly, "and since then, the case has been clueless, and until now, there are still no clues." ”

"I used to want to go to them, but unfortunately, none of my relatives knew where they were, and the task force didn't make any progress — or, for some reason, they didn't dare to make progress." With a wry smile, Wen Yifan looked up at the window and explained: "After all, how can someone who dares to hit them with an idea be a small role?" ”

"So, over the years, you inherited your parents' inheritance, bought this villa, and pretended to be a normal person?" Lin Yunqian let out a long sigh, "I'm sorry, I mentioned your sadness, to be honest, I didn't expect that reality is more ridiculous than illusory." ”

"So, you know why the headmaster pays attention to me like this." Wen Yifan waved his hand, and then said: "I am the largest shareholder of the school, and it is because of this that he can 'trust' me so much. ”

"That's right." Lin Yunqian slowly closed his eyes, as if he was thinking about something.

- If what he said is true, then the headmaster's actions can indeed be explained. And if you don't need to provide proof of identity for the job...... Maybe it's a good thing too?

In this way, he can not only hide his identity further and make his life here more natural, but also further improve his relationship with Wen Yifan. After all, the "writer" would never have imagined that he would be able to work in a school without providing any identification.

"Okay, then I'll go to work tomorrow and give it a try." Lin Yunqian quickly showed a wicked smile, "Someone is in physical education class, but be careful!" ”

Pretending to say this easily, Lin Yunqian secretly left a trace of doubt in his heart.

- Did the police do nothing about the mysterious disappearance of their parents? It can make millionaires disappear without leaving a trace...... Is it possible that it was the hand of the "writer"?

Looking up at the window, Lin Yunqian secretly made up his mind.

- Whether it is the hand of the "writer" or not, it is necessary to help him find out about this case!

- After all, I'm a detective.