I Can View Character Attributes

"Well, it's useless to ask."

Xia Xu also realized this and was a little helpless.

Things seem to be back to square one.

It is indeed a reward to find Pan Long's father's blog, but the only clue now seems to be only photos.

"Could it be some kind of steganography?"

After a moment of thinking again, He Qing suddenly made a suggestion.

Steganography, as the name implies, is to hide the way of writing some kind of information, hiding some kind of information in another thing.

Unlike encrypted communication and cryptography, steganography is not just about keeping third parties from knowing the content of the communication, but going a step further to hide the fact of "communication" itself.

"Wait a minute, let me verify."

Meng Bochao was reminded and downloaded the picture on the blog page.

He first tried to use the simplest way to change the photos into TXT text format or RAR and other compressed file formats to see if he could use this format conversion to hide certain content and files.

After failing to gain anything, he tried more complicated methods one after another, and everyone quietly waited for his results.

"It does seem possible that LSB steganography was used, and the probability of 0 values ​​in the least significant bit of RGB values ​​​​occurring is too high."

After a while, Meng Bochao uttered in high spirits.

"What's the meaning?"

Pan Long was confused by these convoluted professional terms, and he who was most concerned about this matter hurriedly asked.

"LSB is a form of steganography, which is short for least significant bit.

Usually photos are composed of pixels, and the pixels are recorded with three values ​​of R, G, and B, which are also three channel colors of red, green and blue, which are equivalent to the three primary colors, and any color can be formed by RGB values.

The RGB value is represented by a number from 0 to 255, and the number is stored in binary in the computer. The decimal system we commonly use is to enter one digit when the number ten is reached. Binary, as the name implies, is two to one. The simple understanding is that all values ​​​​are used. Regular 0s and 1s are recorded and expressed.

LSB steganography is to modify the least significant bit of the binary value, change the least significant bit 0 to 1, or change 1 to 0, the change of the binary value will cause the RGB value to change, but only a small change, the naked eye It's almost impossible to tell the difference..."

This is great, a large piece of more convoluted conceptual science is spit out from Meng Bochao's mouth, layer by layer, which can be called a Russian nesting doll.

"Stop, bully me because I don't understand computers, right? Tell me the conclusion directly."

Yang Bowen called Meng Bochao to stop.

"Well, to put it simply, the probability of the least significant bit 0 and 1 in the pixel data of a normal photo is close to the same, but the probability of 0 in this photo has greatly exceeded the standard, and it is likely that someone has made changes .”

Meng Bochao stopped showing off resentfully, and simply said: "This kind of modification can't tell the difference with the naked eye, but the written information can be hidden by referring to specific rules, and these rules are also ready-made. There are many general character encoding tables in software development. Different numbers can represent different letters and even Chinese characters."

"So you can decipher the hidden message inside?"

He Qing asked sharply.

"Theoretically, there are only those types of code tables, and you can find out the rules by comparing them, but the problem is that I don't know which pixels are changed. I have tried it just now, and it is not the rule from the first and last pixels. change."

Meng Bochao smiled awkwardly.

The current situation is that he knows that some text information is hidden in it, but he doesn't know which information is hidden.

After all, the pixel value is also represented by numbers, and the result of comparing with the character encoding table is not necessarily the hidden information written.

To describe it simply, it is like a poem with a hidden head or a hidden tail. If you know that it is a hidden head and a hidden tail, you can see it hidden at a glance.

But if it is hidden inside without any rules, it will be difficult to see, unless you figure out the rules or try to form words one by one.

"Isn't this a ready-made control group?"

Xia Xu picked up the physical group photo on top of the briefcase and threw it on Meng Bochao's laptop keyboard.

Meng Bochao was probably a little smug, and he glanced at Xia Xu speechlessly: "This is not photo data. If you take or scan this photo again, there will be a difference in light and dark, and the camera equipment will cause random background noise again. It is impossible to get the same data. original digital image of .

"And what if I could get an original digital photo?"

Xia Xu raised his eyebrows playfully.

"Then I ate the notebook."

Meng Bochao patted his belly.

"Haha, yes, I will be a witness, how about opening a market, do you want to place a bet?"

He Qing booed immediately.

Xia Xu smiled and said: "I don't mind, why don't you just bet on your monthly salary, you win double the salary, and I win you will deduct all of your monthly salary for this month."

"Boss, I support you in terms of personal will, but you directly classify me as the opposite..."

He Qing's heartbroken face turned into an unconcealable smile in an instant: "It can't be blamed on me for not supporting you."

"Of course, I don't blame you. Is there anyone else who wants to participate?"

Xia Xu looked at Yang Bowen and Pan Long playfully. As for Meng Bochao, he naturally participated by default.

"Hey, don't gamble, don't gamble, Lao Yang, I have a family, and I have to hand in my salary, so I can't afford to gamble, but I still support and believe in you, boss."

Yang Bowen politely declined with a very ghostly smile.

As the earliest existence to follow Xia Xu, he knows the capabilities of his boss, and even more that he is well-informed and never does anything he is not sure about.

"I won't gamble..."

Pan Long also refused with a smile.

The reason for this is firstly that Xia Xu has left behind the image of a tall man in the past two days, and the other is that he is a little ashamed to talk about it - he has no money.

He is not an employee here, but just now he inquired casually, the basic salary of people like Yang Bowen starts at 20,000 yuan for free prostitution, how can he have so much money for gambling.

"I, I believe in you too."

Although Tang Youxin didn't participate, she expressed her opinion in a nonchalant manner.

Well, it's so cute, as expected of my little white flower.

Naturally, Xia Xu would not disappoint Xiao Baihua, and reached out to pick up the photo on Meng Bochao's notebook again, and said with a smile: "I can't compare with you in terms of these professional skills, and I am sure I can restore this photo to the original digital negative no way."

This statement is obviously followed by a 'but'.

"However, have you ever thought that Pan Long's father left steganographic messages in the pictures of his blog for covert communication, to be precise, to leave messages for specific people. If this is the case, it must be There is a way to decipher it."

Xia Xu's words really opened up the minds of several people who were stuck in a dead end, but soon they realized that the essence of the problem had not changed. Meng Bochao said directly: "But boss, I also know that there is a deciphering method, but the problem is What is the method of deciphering? Where is it?"

"I said this just to tell you that this deciphering method must exist, and it was left by Pan Long's father, to be precise, the person who left the steganographic message."

Xia Xu smiled, raised the photo in his hand and waved it: "As for the deciphering method, isn't it right here?"

"At this?"

Now everyone was completely stunned.

Because the problem has not changed, they just have no way to get this photo now.

Co-authored and circled seven or eight times and finally returned to the original point? What about our Ouroboros?

Seeing this, Xia Xu could only continue to explain helplessly: "You can't just stare at this photo, this photo is actually just a reminder to let people know of the existence of this photo.

In fact, the key to deciphering requires a different perspective, such as how did this photo come from? Definitely need a digital camera to shoot, right? Definitely need to print it? "

"correct."

Yang Bowen on the side suddenly had an epiphany, and couldn't help but exclaim: "The key point is the source of the photo. The equipment must be used to take this photo, and it is so clear after a long time. Those old machines can't take pictures. It must have been taken with professional equipment in the past. "

"That's right."

Xia Xu chuckled and nodded: "So there should be original digital negatives in the camera, and since Pan Long's father must have left a deciphering method, then the camera must still be there, and the original negatives in the camera must also be kept.

As for where to keep it, it is also obvious that this reminder photo is in Pan Long’s home, so the only ones who are most likely to get the photo are Pan Long and his family. The camera or backup digital negatives must stay with them. Or the way to develop and print this photo. "

"Fuck, boss, you are amazing."

Everyone suddenly became enlightened, and then all looked at Pan Long.

"I do have an old-fashioned digital camera at home, but I have never used it. I didn't understand it when I was a child. When I grew up, it would have been turned off and turned off for a long time, eating ashes at the bottom of the cabinet."

Pan Long understood what they meant, and he looked a little excited, recalling.

"Then what are you waiting for, go back and get it."

Meng Bochao urged.

"I can't see that you are quite warm-hearted, but don't forget, you can't go back on your bets, and I won't pay you two salaries this month."

Xia Xu reminded with a smile.

Meng Bochao: "..."

"Boss, I was wrong, don't deduct my salary, I am innocent, obviously you took the initiative to put me in the enemy camp, I am in the enemy camp, and I have a heart~"

He Qing, who was reminded and realized this crop, wanted to cry instantly but had no tears.

"Hahaha, you deserve it."

Yang Bowen immediately gloated.

Watching you lose money is more refreshing than making money by myself.

"Miss Boss, help me to say something nice~"

Compared to He Qing, Meng Bochao clearly realized who his savior was, and looked at Tang Youxin eagerly.

It's a pity that classmate Xiao Tang glanced to the side erratically, pretending not to hear.

╭(╯^╰)╮Hmph, I told you not to believe him, but you still want me to beg for mercy, it's a beautiful idea.

I'm also very petty.