"My email?" Lin Wan looked confused, stepped forward and took the slightly larger email from the dormitory auntie. It looked like a book rather than a letter.
The entire envelope was wrapped in a light yellow cover, with a stamp in the upper right corner and a series of dignified and elegant block letters written below. Lin Wan looked at the mailing list and carefully checked the relevant information.
There is a paragraph at the end below - Classmate Lin Wan, my sincere greetings.
Zhang San?!
Lin Wan was stunned when she saw the name 'Zhang San', her brows slightly furrowed, and her mind suddenly recalled Zhang San's classmate Zhang San who had been searching to no avail a few days ago, and Zhang San's version of the arithmetic problem collection that was popular in major schools.
The first time she met Zhang San, it was a warning note. When she met Zhang San again, it was a collection of wrong math questions. Today, this 'Zhang San' actually sent her an email.
This behavior reveals a lot of information. First of all, this Zhang San knows her address and information. From this, it can be shown that ‘Zhang San’ has a high probability of knowing her.
Either the people around you or your classmates at school, the latter is more likely.
"What do you mean by sending me this email?" Lin Wan was confused. She thought about Zhang San's intention, but to no avail. She took a deep breath, picked up the package and turned to walk to the dormitory.
Going up the stairs and returning to the dormitory, there was no one in the room.
Taking advantage of this gap, Lin Wan opened the package. It was full of study supplies, including a familiar collection of arithmetic problems, a Chinese book, and a notebook. The three of them looked ordinary and inconspicuous.
Seeing the three things, Lin Wan frowned slightly, picked up the arithmetic problem book with her right hand, and looked through it, but found nothing special.
This is a normal collection of wrong questions.
I continued to check the Chinese documents of high schools, and the results were the same as above.
"What's going on? Did you send me some school supplies?" Lin Wan was confused, and her eyes fell on the notebook placed at the bottom. The style and size were the most common notebooks on the market. Apart from being extremely brand-new, there was nothing else.
Valid information.
Lin Wan took out her notebook and opened the new notebook cover with her hand. Suddenly, the first page full of mathematical characters came into view.
This is a math problem. It is written in block letters. It is the only math problem on the entire first page.
"You want me to solve the problem?" Lin Wan frowned slightly, thoughtfully, and looked at the math problem with her eyes.
This question seems simple, but in fact it is extremely complex. It is a question about functions.
After looking at it for about five minutes, Lin Wan finally had an idea for solving the problem. She picked up the scratch paper and pen in her right hand and calculated it, and finally got the result of 198.
198?
After coming up with this number, Lin Wan, who has a very high IQ, thought briefly and couldn't help but look at the collection of wrong arithmetic questions.
Among the three items, only the collection of arithmetic errors has more than 200 pages.
Hope I'm not wrong.
Lin Wan took a deep breath, picked up the book of wrong math questions, and turned the pages according to memory.
Sure enough, as I turned to page 198, a previously undiscovered situation appeared. Pages 198 and 199 seemed to have been artificially processed. The surfaces were sticky and formed a whole. There was a gap between the two pages, and there was a
A piece of paper, if you flip through it casually, you will just skim over it.
When Lin Wan saw the paper hidden between the two pages, her heart beat slightly faster. She held her breath and carefully took out the slightly yellowed letter and opened it.
Hello, classmate Lin Wan.
If you successfully see this, it means that the secret of the notebook has not been leaked, neither the postman nor the Blue Clothes Club has discovered it. This is my victory and your luck.
Please remember this day, it deserves congratulations.
Classmate Lin Wan, please read the following content in a safe environment, because once the secrets in the notebook are leaked, it will trigger an endless pursuit by the Blue Clothes Club and the Japanese. Your life will be in danger, and so will I.
There will be.
This is top-secret information that I risk my life to pass on to you. Please solve the second math problem.
——Zhang San.
"Top secret information!" Lin Wan's expression suddenly became solemn after reading the last sentence of the first paragraph of the letter. Secretly, as the person in charge of the youth organization of Peking No. 4 Middle School, she was keenly aware of the importance of this email through the content of the letter.
What would be the thing that the Blue Clothes Club and the Japanese care about most?
have no idea.
But no matter what it is, one thing is certain - it is good for the organization.
Lin Wan was highly alert, and immediately followed Zhang San's request, quickly got up, went to the door, and locked the door.
The function of the door lock is not to isolate the roommate, but to prevent the roommate from suddenly entering the dormitory and give her enough time to react.
At this stage, the dormitory is the only safe environment where she can read the content behind.
Lin Wan didn't know why such top-secret information was delivered by email, but she chose to believe it.
Because, the signature on the letter paper is——Zhang San.
Although Lin Wan was very curious about this person's true identity, in Lin Wan's heart, he was a good person who was full of goodwill towards the organization.
Now, this good man is risking his life to deliver top-secret information to her.
A safe environment was established, and Lin Wan was the only one left in the dormitory.
There was not much time left, and her roommate would return soon. Lin Wan needed to seize the time to understand the situation, and returned to the table. This time she picked up the letter quite solemnly, and concentrated on solving the problem. After three minutes passed, she calculated
Lin Wan, who got the correct answer, turned to page 88 as quickly as possible.
Pages 88 and 89 also form a gap.
Inside is a second piece of paper.
Taking out the letter paper, Lin Wan took a deep breath and read the text carefully.
Lin Wan, if you see this letter, it means that you have confirmed that you are staying in a safe environment. Let's get to the point.
The cause of the incident came from the Blue Clothes Club's attempt to decipher Japan's latest upgraded cryptography system-Red Secret, which is a common cryptography system used by Japanese diplomacy and the Japanese Army. Its main users include the Japanese Garrison Army, the Kwantung Army, and the Japanese Embassy in China.
Local diplomacy, etc., contains a large amount of important intelligence information every day.
Upgraded in January this year, coming from the green secret system, the Blue Clothes Secret Service tried to decipher the red secret. However, because the red secret used the Hill cipher mechanism, the deciphering work has not made progress. Recently, after I joined the deciphering work,
The progress is gratifying, and the red secret has been fully deciphered not long ago.
At this point, I believe you have guessed what the secret in the notebook is.
Yes, that’s right, the secret in the notebook is the Japanese Red Secret deciphering information. The Japanese Red Secret is based on mathematical matrix theory, and its properties are substitution codes + alphabetic codes. The notebook contains the Red Secret matrix mathematical model, calculation formulas, and alphabets.
and codebook.
The codebook is divided into diplomatic and military, consisting of different types of phrases.
With this cryptographic information, you only need to find a college student who understands matrix theory to completely decipher the intelligence information of Japanese diplomacy and the Japanese army, and thus understand the other party's movements.
I believe that with your mind and experience, you should understand the importance of this red secret deciphering information.
Therefore, classmate Lin Wan, I hope you will do your best to protect it and hand it over to the organization as soon as possible. Be careful not to expose it.
Once exposed, the Japanese will not only launch a crazy hunt for you, but also change the encryption system immediately, making the results of deciphering the red secret useless. The Blue Clothes Club will also become suspicious of me and others who have participated in the deciphering work.
.
As soon as possible, confidentially, is the requirement.
I have taken confidentiality measures in the notebook. The entire red secret deciphering information is written with cobalt chloride material, and all the information is invisible. You need to tear out each page and bake it on the stove before the information content will be revealed.
Lin Wan, I know that you are a student of Peking No. 4 Middle School, and I also know that you are a member of the Red Organization. However, I cannot tell you your true identity, nor can I tell you any details or other information about the work of deciphering the Red Code. Please also
Don't come to me.
The only thing I can tell you is that my name is Zhang San. I am both an outlaw and a patriotic scholar. I look forward to meeting you one day with my true identity.
For the sake of China and the Chinese nation, we must forge ahead.
Don't let me down.
——April 6, 1937, Zhang San.
silence.
Deathly silence.
There was silence in the room.
"Mr. Zhang San, Jin Yu will not disappoint you, will not expose the information and make your hard work go to waste..." The right hand holding the second piece of letter paper trembled slightly. Lin Wan's eyes flashed slightly after reading the entire letter.
Hong, the emotions in his heart were extremely complicated. In the end, he suppressed his emotions forcibly, and his jewel-like eyes revealed a touch of determination.