Repair the world of Conan

Mouri Kogoro didn't know Shitara Shigeyoshi, so he thought it was a prank. Conan didn't think so. He felt that since the other party secretly put U into Xiaolan's bag, there must be some special reason.

As for the uncle not knowing him, that's normal. After all, he doesn't know all of the clients.

So Xiaolan and Conan took the encrypted U and ran to Dr. Ali's house to find a way to crack it.

"Doctor, can this code be solved? Conan asked, and Xiaolan also looked at the doctor expectantly.

"It is possible, but I am not a professional at this, so I can only use brute force to crack it, which will be very slow.……"The doctor spoke first. In the past, it was relatively easy to crack passwords in the floppy disk era, but now with the advancement of encryption methods, it has become difficult to crack passwords.

Xiaolan was a little confused,"What is brute force cracking?"

Xiao Ai, who was watching the show, explained calmly:"There are two commonly used methods to crack passwords: dictionary cracking and brute force cracking. Dictionary cracking is to collect passwords that are frequently used. Try to crack; brute force cracking, also known as the exhaustive method, is to try all combinations of alphanumeric symbols in turn. The more complex the password, the longer it will take."

"How long does it take to crack a brute force attack?" Conan asked.

The doctor replied:"If the password is short, it may only have 1 or 2 digits. If it is long, it may have 256 digits. If you are unlucky and encounter a long password, the time taken is calculated in 390 years.……"

Conan almost fell down, calculated in years? Then what a fool I am!

"Is there any other way?"Xiaolan also looked very anxious, because she had an ominous premonition in her heart.

"This...I have no other choice……"

At this time, Xiao Ai on the side suggested,"Why don't you ask Ye Ling to try it?" Xiao Ai was also very interested in this encrypted USB flash drive, because the story sounded like a spy movie.……

"Yes, you can try it with Ye Ling. His computer skills seem to be very good."The doctor also agreed.

Conan really couldn't think of any other way and could only accept the suggestions of the two of them.

……

Soon Xiaolan and Conan arrived at the door of Ye Ling's house, and Xiaoai followed closely behind. After ringing the doorbell, Ye Ling opened the door soon. When he saw three people standing outside the door, Ye Ling was a little surprised.

"Why are you here?"

"Ye Ling, I want to ask you for a favor……"Xiaolan and Yuanzi have completely different personalities. Yuanzi asked Ye Ling for help before, but Xiaolan was cautious when asking others for help, for fear of making others unhappy.

"Come in and talk about what happened."

Ye Ling invited them to the villa. Yu Xiaolan really likes this girl. Of course, there are many kinds of likes. Likes are not necessarily between men and women, but can also be a kind of appreciation. For example, some people like books, and some people like music..

Conan couldn't wait, and took out the U and asked:"Ye Ling...Brother, there is an encrypted compressed package in the disk. Can you crack the password and read the contents?"

Around Xiaolan, Conan was forced to add the title of brother when he called Ye Ling, which made Conan feel as if he had eaten a fly and felt very uncomfortable. But it can’t be done until he asks for help from others……

"oh? Let me see."Ye Ling took U over, connected it to his laptop, and started trying to open the file. As expected, he was blocked by the password."The length of the password is unknown. It would take hundreds of years to crack it with violence."

"Hundreds of years?"Conan and Xiaolan were shocked. Ye Ling's statement was actually more exaggerated than Dr. Ali's?

Xiao Ai didn't show any expression. She knew that hundreds of years would be less... With the advancement of encryption methods , even if some passwords are cracked by a supercomputer, it will take hundreds of millions of years to crack them. Only quantum computers can be cracked"quickly", but how many countries can possess quantum computers, which are more advanced than nuclear weapons?

If not If I remember correctly, only two countries, China and the United States, are currently public.

"Is there any other way?"Xiao Ai asked tentatively, because from Ye Ling's tone, it seemed that he had other methods besides violent cracking.

"Yes, you can also use physical means to crack it"

"Physical crack?"Conan and Xiao Ai were both stunned. Xiaolan didn't know much about computers, but she didn't feel anything. (bibf)

"To be precise, it is a combination of software and hardware. Ye Ling replied.

Conan asked suspiciously:"You don't want to disassemble the U and connect it to a machine to directly read the contents of the memory chip, right?" If it is external encryption, the password can indeed be bypassed in this way, but the password is added to the file. If you remove the U, what you read will still be an encrypted compressed package?"

"of course not."Ye Ling smiled and said,"When the computer checks the password, it does not do a series of numbers at the same time. This is limited by the laws of physics. For example, if you enter 1234 passwords, the computer will first check from 1, and then verify the number 2 after passing it. Therefore, if characters on different digits are wrong, the verification time is also different."

Xiao Lan was still puzzled.

Xiao Ai had already understood and explained:"For example, the correct password is 1234. Although you enter 0000 and 1230 are both wrong passwords, the computer will check 0000 faster than 1230. Because 0000 is wrong from the first digit, and the first three digits of 1230 will be verified, and the error will not occur until the fourth digit."

This is indeed limited by the laws of physics. It is impossible for a computer to calculate a large amount of data at the same time, even with a multi-core CPU. Even if it seems to people that the computer completes all calculations at the same time, in the calculation and internal, these tasks are actually There is still a priority.

If you can know which number of the password is wrong, then you can crack it one by one starting from the first number of the password, and you can solve it very easily.���Password, even if the password is 256 characters or longer.

After hearing this, Xiao Lan couldn't help but stare at Xiao Ai in astonishment. Isn't this child too capable of understanding?

"However, although there is a time difference between different digits in the password, it is impossible for anyone to notice the time difference?"Conan also figured out the principle and couldn't help but frowned.

"Yes, it's impossible for humans to detect it, but computers can."Ye Ling said with a smile:"That's why I have to combine software and hardware. I use the software I developed to capture the time difference of hundreds of millions of seconds."

……

Ye Ling did develop such a software, using a programming language he invented himself. Just as he said, he opened the program to monitor the password input box, and then the computer automatically filled in the password, testing each character one by one.

Xiao Ai stared at Ye Ling unblinkingly. Ever since she had that dream, she had always felt that Ye Ling was the fake gin from two months ago. She was full of curiosity about Ye Ling, and even she didn't realize that this curiosity was actually abnormal.

Soon, the passwords were tried one by one starting from the first one.

This is a string of meaningless characters with both large and small alphanumeric symbols, and is highly confidential.

"What is this? Xls file? Exce1 form?"Looking at the two decompressed files, Conan asked subconsciously._

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