It is indeed a reward to find Pan Long's father's blog, but the only clue now seems to be photos.
"Could it be some kind of steganography?"
Once again lost in thought, He Qing suddenly made a suggestion.
Steganography, as the name suggests, is to hide the way of writing certain information, hiding certain information in another thing.
Different from encrypted communications and cryptography, steganography is not just about preventing third parties from knowing the content of communication, but it also goes a step further and hides the fact that "communication is taking place" itself.
"Wait a minute, let me verify it."
Meng Bochao was reminded and downloaded the picture from the blog page.
He first tried the simplest way, changing the photos into txt text format or rar and other compressed file formats to see if this format conversion could be used to hide certain content and files.
After getting no results, he tried more complicated methods one after another, and everyone quietly waited for his results.
"It seems that it is indeed possible to use lsb steganography. The probability of 0 appearing in the least significant bit of the rgb value is too high."
After a while, Meng Bochao spoke out in high spirits.
"What's the meaning?"
Pan Long was confused by these convoluted professional terms. He was most concerned about this matter and quickly asked.
"LSB is a steganography method, which is the abbreviation of least significant bit.
Usually photos are composed of pixels, and pixels are recorded with three values of r, g, and b, which are the three channel colors of red, green, and blue. They are equivalent to the three primary colors, and any color can be formed from the rgb value.
The RGB value is represented by numbers from 0 to 255, and numbers are stored in binary in computers. The decimal system we commonly use is to add one digit to the number ten. Binary, as the name suggests, is two to one. A simple understanding is that all values are
Regular 0s and 1s are recorded and expressed.
LSB steganography is to modify the least significant bit of the binary value, changing the least significant bit of 0 to 1, or changing 1 to 0. After the binary value is changed, the RGB value will change, but it is only a very small change, and the naked eye
It’s almost impossible to tell the difference…”
This is great, a long piece of more convoluted concept science came out of Meng Bochao's mouth, layer by layer, it can be called a Russian matryoshka doll.
"Stop, you are bullying me because I don't understand computers, right? Just tell me the conclusion."
Yang Bowen asked Meng Bochao to stop.
"Well, to put it simply, the probability of the least significant bits 0 and 1 appearing in the pixel data of a normal photo is close to the same, but the probability of the 0 value appearing in this photo greatly exceeds the standard. It is likely that someone has made changes.
.”
Meng Bochao angrily stopped showing off and simply said: "This kind of change cannot be discerned with the naked eye, but the written information can be hidden by referring to specific rules, and these rules are also readily available. There are many jointly formulated character encoding tables in software development.
, different numbers can represent different letters or even Chinese characters.”
"So you can decipher the hidden information inside?"
He Qing asked sharply.
"Theoretically, this is the case. There are only a few types of coding tables. You can find out the rules 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 was not done from the first and last pixels.
The rules change.”
Meng Bochao laughed awkwardly.
The current situation is that he knows that there is some text information hidden in it, but he does not know that it is hidden information.
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 describe it simply, it is like a poem with an acrostic head or a hidden tail. If you know that it has an acrostic head and a hidden tail, you can naturally tell the hidden part at a glance.
But if there is no pattern hidden in it, it will be difficult to see it, 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 that was placed on top of his briefcase and threw it on Meng Bochao's laptop keyboard.
Meng Bochao was probably a little carried away and glanced at Xia Xu speechlessly: "This is not photo data. Taking or scanning this photo will also produce differences in light and darkness, and the camera equipment will cause random noise again. It is impossible to get the same result.
original digital image.”
“What if I could get the original digital photo?”
Xia Xu raised his eyebrows in amusement.
"Then I'll eat the notebook."
Meng Bochao patted his big belly.
"Haha, okay, okay, I will bear witness. How about we open a market? Do you want to place a bet?"
He Qing immediately started booing.
Xia Xu said with a smile: "I don't mind, why don't I bet on 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 directly put me on the opposite side..."
He Qing had a look of sorrow on his face, but then it instantly turned into a smile that couldn't be concealed: "You can't blame 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, I don't want to gamble. Lao Yang, I have a family. I have to hand over my salary and I can't afford to gamble. However, I still support and believe in you, boss."
Yang Bowen declined with a very devilish smile.
As the first person to follow Xia Xu, he knew what his boss was capable of. He also knew that he was well-informed and never did anything he was unsure of.
"I won't bet..."
Pan Long also laughed and refused.
The reason for this is firstly because of the high-ranking image Xia Xu has left in the past two days, and secondly because he is a little embarrassed to say it - he has no money.
He is not an employee here, but he just casually inquired about it. People like Yang Bowen's basic salary starts at 20,000 yuan for no work but for prostitution. How could he have so much money for gambling?
"I, I believe you too."
Although Tang Youxin did not participate, she still expressed her position in a soft voice.
Well, it’s so cute. It’s worthy of being my little white flower.
Naturally, Xia Xu would not disappoint Xiao Baihua. He reached out again to pick up the photo on Meng Bochao's notebook and said with a smile: "I can't compete with you in terms of these professional skills. I can really restore this photo to the original digital negative."
no way."
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 precise, he left messages for specific people. In this case, it must be a message left behind.
There are ways 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 way to decipher it, but the problem is
What is the method of deciphering? Where is it?"
"I only say this to tell you that this method of deciphering must exist, and it was left by Pan Long's father. To be precise, it was left by the person who left the steganographic information."
Xia Xu smiled, raised the photo in his hand and said, "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 started with this photo.
After seven or eight rounds of co-writing, we finally returned to the starting point? What about 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 actual key to decryption requires a different thinking 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 on the side suddenly had an epiphany and couldn't help but exclaimed: "The key point is the source of the photo. You must have equipment to take this photo, and it is so clear even though it is so old. Those old cameras cannot take it. It must have been taken with professional equipment from 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 behind the deciphering method, the camera must still be there, and the original negatives in the camera must also be retained.
As for where to keep it, it is obvious. This photo that serves as a reminder is placed at Pan Long’s house, so the only people who are most likely to get it are Pan Long and his family. The camera or backup digital negatives must be left with them, or maybe It’s in the process of developing and printing this photo.”
"Damn it, boss, you are so amazing."
Everyone suddenly became enlightened and then all looked at Pan Long.
"I do have an old-fashioned digital camera at home, but I haven't used it. I didn't understand it when I was a kid. When I got older, the thing had long been out of power and turned off, gathering dust at the bottom of the cabinet."
Pan Long understood what they meant, and he looked a little excited as he recalled.
"What are you waiting for here? Go back and get it quickly."
Meng Bochao urged.
"I don't see that you are quite enthusiastic, but don't forget, you can't default on your bets. I won't pay your salary this month."
Xia Xu reminded with a smile.
Meng Bochao: "..."
"Boss, I was wrong. Don't deduct my salary. I am innocent. It was obviously you who took the initiative to assign me to the enemy camp. I am in the enemy camp and my heart is with Han~"
He Qing, who was reminded of this incident, was on the verge of tears.
"Hahaha, you deserve it."
Yang Bowen immediately gloated.
Watching you lose money is more satisfying than making money myself.
"Lady boss, please help me and say something nice~"
Compared to He Qing, Meng Bochao clearly understood who his savior was and looked at Tang Youxin eagerly.
Unfortunately, classmate Xiao Tang glanced to the side erratically, pretending not to hear.
╭(╯^╰)╮Hmph, I told you not to believe him, but now you still want me to beg for mercy. It’s a beautiful idea.
