"Well, it's useless to ask."
Xia Xu also realized this and felt helpless.
Things seem to have come full circle.
Finding Pan Long’s father’s blog is indeed a gain, but the only clues now seem to be just the photos.
"Could it be some kind of steganography?"
After a moment of thinking again, He Qing suddenly made a suggestion.
Steganography, as the name suggests, is a way of hiding a certain information, hiding a certain information in another thing.
Different from encrypted communication and cryptography, steganography is not just about preventing third parties from knowing the content of communication, but also about hiding the very act of "communication".
"Wait a minute, let me verify it."
Meng Bochao was reminded and downloaded the picture on the blog page.
He first tried the simplest method, changing the photos into TXT text format or compressed file formats such as RAR to see if this format conversion could be used to hide certain content and files.
After failing to gain any results, he tried more complicated methods, and everyone was quietly waiting for his results.
"It does seem possible that LSB steganography was used, as the probability of a 0 value appearing in the least significant bit of the RGB value is too high."
After a while, Meng Bochao spoke excitedly.
"What's the meaning?"
Pan Long was confused by these tongue-twisting professional terms, and as he was most concerned about the matter, he immediately asked questions.
“LSB is a steganographic term, which stands for Least Significant Bit.
Usually photos are made up of pixels, and pixels are recorded as three values R, G, and B, that is, the three channel colors of red, green, and blue. Just like the three primary colors, any color can be constructed by RGB values.
The RGB value is represented by a number from 0 to 255. The numbers are stored in binary in the computer. The decimal system we often use advances one digit when the number reaches ten. Binary system, as the name suggests, is two-into-one. In simple terms, all values are recorded and expressed in a regular manner using 0 and 1.
LSB steganography is to modify the least significant bit of the binary value, changing the least significant bit 0 to 1, or changing 1 to 0. The change in the binary value will cause the RGB value to change, but it is only a very small change, and it is almost impossible to distinguish the difference with the naked eye..."
Now, a long and even more complicated section of popular science concepts came out of Meng Bochao's mouth, one layer within another, like a Russian nesting doll.
"Stop, you're bullying me because I don't know computers, right? Just tell me the conclusion."
Yang Bowen was a little overwhelmed and stopped Meng Bochao.
"Well, to put it simply, the probability of the least significant bit 0 and 1 appearing in the pixel data of a normal photo is almost equal, but the probability of the value 0 appearing in this photo exceeds the standard. It is very likely that someone has modified it."
Meng Bochao stopped showing off in a sullen manner and said simply: "This kind of modification cannot be distinguished by the naked eye, but by referring to specific rules, the written information can be hidden, and these rules are also ready-made. There are many commonly formulated character encoding tables in software development. Different numbers can represent different letters or even Chinese characters."
"So you can decipher the hidden message inside?"
He Qing asked pointedly.
"That's right in theory. There are only a few types of coding tables, and we can find the pattern by comparing them. But the problem is that I don't know which pixels have been changed. I have tried it just now, and it's not a regular change from the first to the last pixel."
Meng Bochao smiled awkwardly.
The current situation is that he knows that there are certain text messages hidden in it, but he doesn't know what those are hidden messages.
After all, pixel values are also represented by numbers, and the result after comparing with the character encoding table is not necessarily the hidden information written.
To put it simply, it is like a poem with a hidden beginning or a hidden end. If you know it has a hidden beginning or a hidden end, you can naturally tell at a glance that it is hidden.
But if it is hidden in there without any pattern, it will be difficult to see, unless you figure out the pattern or try to form words one by one.
“Isn’t this a ready-made control group?”
Xia Xu picked up the physical photo on top of the briefcase and threw it onto Meng Bochao's laptop keyboard.
Meng Bochao was probably a little too proud of himself, and glanced at Xia Xu speechlessly: "This is not photo data. Taking or scanning this photo again will also produce differences in light and darkness. The camera equipment will also create random background noise again. It is impossible to get the same original digital image."
“What if I can get the original digital photo?”
Xia Xu raised his eyebrows slightly with a playful look on his face.
"Then I ate the notebook."
Meng Bochao patted his big belly.
"Haha, sure, sure. I'll be a witness. How about we open a betting market? Do you want to place a bet?"
He Qing immediately started to make a fuss.
Xia Xu smiled and said, "I don't mind. How about we bet your monthly salary? If you win, your salary will be doubled. If I win, your monthly salary will be deducted in full."
"Boss, I support you personally, but you put me on the opposite side so directly..."
He Qing looked distressed, but then he immediately turned into an unconcealable smile: "You can't blame me for not supporting you."
"Of course, I don't blame you. Is there anyone else who wants to join?"
Xia Xu looked at Yang Bowen and Pan Long with amusement. As for Meng Bochao, he naturally agreed to participate.
"Hehe, no gambling, no gambling. Old Yang, I'm a family man. I have to hand over my salary, so I can't afford to gamble. But I still support and believe in you mentally."
Yang Bowen declined with a sly smile.
As one of the earliest followers of Xia Xu, he knew his boss's capabilities. He also knew that he was well-informed and would never do anything without certainty.
"I won't gamble..."
Pan Long also smiled and refused.
The reason for this is, firstly, due to the high-class image that Xia Xu left in the past two days, and secondly, it is a bit embarrassing to talk about it - he has no money.
He is not an employee here, but he just asked around and found out that people like Yang Bowen get a base salary of 20,000 yuan for free without doing any work. How could he have so much money for gambling
"I, I believe you too."
Although Tang Youxin did not participate, she also expressed her opinion in a soft voice.
Well, it’s so cute, it’s worthy of being my little white flower.
Xia Xu naturally would not let Little White Flower down. He reached out and picked up the photo from Meng Bochao's notebook again, and said with a smile, "I can't compare with you in terms of these professional skills. I really can't restore this photo to its original digital negative."
This statement is obviously followed by a 'but'.
"But have you ever thought that Pan Long's father left hidden messages in the pictures on his blog for covert communication. To be more precise, he left messages for specific people. If that's the case, there must be a way to decipher it."
Xia Xu's words did open up the minds of the people who were stuck in a dead end, but they soon realized that the essence of the problem had not changed. Meng Bochao said directly: "But boss, I also know there is a way to decrypt it, but the question is what is the decryption method? Where is it?"
"I said this just to tell you that this method of decryption must exist, and it was left by Pan Long's father, or more precisely, the person who left the steganographic message."
Xia Xu smiled and raised the photo in his hand: "As for the decryption method, isn't it here?"
"Here?"
Now everyone was completely confused.
Because the problem hasn't changed, they now have no idea where to start with this photo.
So after going around in circles for seven or eight times, we finally return to the starting point? Where is the 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 that this photo exists.
The key to deciphering the secret actually requires changing your perspective. For example, where did this photo come from? It must have been taken with a digital camera, right? It must have been developed and printed, right? "
"yes."
Yang Bowen, who was standing by, suddenly realized something and couldn't help but applaud: "The key point is the source of the photo. It must have taken some equipment to take this photo. And it's so clear even after so many years. Those old cameras can't take it. 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 way to decrypt it, the camera must still be there, and the original negatives in the camera must also be preserved.
As for where it is kept, it is also obvious. This photo, which serves as a reminder, is placed in Pan Long's home, so the most likely people to get it are Pan Long and his family. The camera or backup digital negative must be left with them, or it may be in the process of developing and printing this photo. "
"Fuck, boss, you are amazing."
Everyone suddenly understood and turned their eyes to Pan Long.
"I think I do have an old digital camera at home, but I've never used it. I didn't understand it when I was a kid, and when I grew up, it ran out of power and was turned off, gathering dust at the bottom of the cabinet."
Pan Long understood what they meant, and his expression became somewhat excited as he spoke while recalling the past.
"What are you waiting for here? Go back and get it."
Meng Bochao urged.
"I didn't realize you're so kindhearted, but don't forget, you can't default on your bet. I won't pay you two your salaries this month."
Xia Xu reminded with a smile.
Meng Bochao: “…”
"Boss, I was wrong. Please don't deduct my salary. I am innocent. It was you who took the initiative to assign me to the enemy camp. I am in the enemy camp but my heart is with Han~"
After being reminded of this, He Qing felt like crying but had no tears left.
"Hahaha, you deserve it."
Yang Bowen immediately felt gloating.
Watching you lose money is more satisfying than making money myself.
"Madam boss, please help me say something good~"
Compared to He Qing, Meng Bochao was more aware of who his savior was and looked eagerly at Tang Youxin.
Unfortunately, classmate Xiao Tang glanced away and pretended not to hear.
╭(╯^╰)╮Huh, I told you not to believe him, and now you want me to beg for mercy? You’re wishing.
I'm also very stingy.