diskusbooks Chapter 163 Cryptographer
Chapter 163 Cryptographer
Now that the man in the dream has appeared, the only thing that doesn't match the information in the dream warning device is...
The only problem is that Lin Chen's seat was not in first class.
However, all of this became clear when he began boarding the plane.
It turned out that Lin Chen's seat had two tickets due to a ticketing system malfunction.
His seat was now taken by the passenger in front of him, so to make up for his mistake, Lin Chen's seat was immediately upgraded from economy class to first class.
When Lin Chen arrived in first class and saw Luo Rui'an sitting next to him, he couldn't help but sigh inwardly.
Sure enough, everything eventually matched the images in the dream warning device.
"Lin Chen, what a coincidence!"
"Yes."
After greeting Luo Rui'an, Lin Chen sat down next to him.
Looking at the flight attendants coming and going around him, Lin Chen confirmed that there was still some time before the plane took off, and then began to observe the man named Luo Rui'an again.
Just before boarding the plane, a sudden thought flashed through his mind, and he began to suspect the man in front of him, feeling that he might be the real trigger for the disaster that followed.
This idea came out of nowhere; it was just a flash of inspiration for Lin Chen.
To confirm this, we need more clues and intelligence.
From his appearance, Luo Rui'an looks like a scholar. Although he is only 10 years older than Xiao Li, his hair is already completely gray.
His facial skin was wrinkled and he looked extremely haggard.
But he seemed to be in good spirits, with a faint smile on his face.
Besides that, what Lin Chen cared about most was a black briefcase next to Luo Rui'an.
The suitcase wasn't big; it looked like it could only hold a few sheets of A4 paper.
However, Luo Rui'an always carried the suitcase with him, even after he was seated, he kept it by his side and never left it.
Lin Chen asked, "Uncle Luo, I didn't have a chance to ask earlier, what industry do you work in?"
“Speaking of which, you and I are practically colleagues…” Roryn said with a smile.
Lin Chen's heart skipped a beat: "You're a mathematician?"
"Ah."
Luo Rui'an nodded and said, "In college, I studied number theory. Later, when the university opened up to the outside world, I was noticed by a foreign professor who came to the school for an exchange program and was recommended to go to Stanford to study cryptography."
Cryptography?
This was the first time Lin Chen had ever heard of this major.
"Cryptography is actually the study of various encryption algorithms. To learn cryptography, you must have a solid mathematical foundation, especially knowledge of number theory, algebra, and other related fields."
"Since you won a gold medal in the International Mathematical Olympiad, you might have a talent for it too. How about giving it a try?"
"Okay."
Upon hearing this, Luo Rui'an immediately called over the flight attendants and asked them for paper and pen.
While the flight attendants were busy serving Luo Rui'an, Lin Chen watched silently from the side, lost in thought.
After receiving the paper and pen, Rorian didn't immediately pose a question. Instead, he asked, "Little friend, do you know the Caesar cipher?"
Seeing Lin Chen's confused expression, Luo Rui'an explained: "The Caesar cipher is a simple substitution encryption technique that encrypts by shifting the letters in the plaintext alphabetically by a fixed offset, and decryption is the reverse operation."
"To give a simple example, if the offset is one, then in a file encrypted with the Caesar cipher, letter A would be written as letter B, letter B would be C, and so on, until letter Z would be written as A."
That concludes the explanation. Now, let's move on to the questions:
I have the following ciphertext: WKH TXLFN EURZQ IRA MXPSV RYHU WKH ODCB GRJ. It is known to be encrypted using a Caesar cipher. Please try to crack the offset and recover the plaintext.
After writing the question on a piece of paper, Luo Rui'an handed the paper and pen to Lin Chen with great interest.
"How about it? Can you solve it?"
Lin Chen hesitated for only a moment before writing down an English sentence on the paper.
the quick brown fox jumps over the lazy dog
"?"
Rorian's eyes widened instantly, staring at him in disbelief.
"What...what's your line of thinking?"
"WKH appears twice in this ciphertext. The most common three-letter words in English are THE, AND, FOR, etc. Assuming WKH corresponds to THE, then the offset of this ciphertext is 3."
"Based on this, I deciphered the entire ciphertext and got this sentence."
"I remember this phrase being commonly used in English to test fonts, keyboards, or typewriters because it contains all 26 letters of the English alphabet. All my assumptions are clearly correct..."
After hearing Lin Chen's explanation, Luo Rui'an's eyes widened even more.
Although Lin Chen's guess had an element of luck, Luo Rui'an gleaned a lot from his words.
The Caesar cipher is just one of the most basic types of cryptography, and it is not difficult to crack.
What's remarkable is that this kid, on his first encounter with it, has already completely grasped the principles and logic within just a few minutes.
This is quite serious.
For a moment, Luo Rui'an couldn't help but introduce more types of codes to Lin Chen, wanting to test his abilities.
The result delighted him.
First, the password is replaced, then the password is replaced.
Regardless of the type of password, Lin Chen quickly mastered it after only a short initial exposure.
It was as if he had been learning these codes for years.
This ability to accept new things, his logical reasoning skills, and Lin Chen's sensitivity to numbers made Luo Rui'an exclaim inwardly.
He's a born cryptography genius!
Having spent 30 years abroad, Roryan had met many cryptography geniuses, but this was the first time he had encountered a genius as young as Lin Chen, who also shared the same Chinese blood!
As the two were talking, the plane completed its takeoff preparations and took off smoothly.
Looking out at the pitch-black night.
Lin Chen already knew that if the future he saw in the dream warning device was followed...
He might continue talking with Roryn along the way until disaster strikes.
But now that things have come to this, he certainly can't do that.
But before he could figure out exactly how the crisis happened, he had to figure out one thing.
"Uncle Luo, I'd like to put the cryptography stuff aside for now. Could you tell me what you actually do for a living?"
"I?"
Luo Rui'an paused for a moment, seemingly not really interested in talking about work.
"Little friend, there's nothing to talk about about my job; it's all in the past."
"Past tense?"
"Yes, after I return to China this time, I will probably be parting ways with my past life, so there's nothing more to talk about..."
Lin Chen hesitated for a moment: "Uncle Luo, is there any possibility that someone doesn't want you to return to China?"
Luo Rui'an's expression changed, and he suddenly became wary.
"Why do you say that?"
"Since you work in the United States, why don't you just go back from the United States? Why do you come to Malaya first?"
You just said you wanted to break free from your past, but you only have a small suitcase with you... Are you afraid people will find out you want to go back to your country?
The wariness between Luo Rui'an's brows grew stronger.
He seemed to suddenly lose interest in chatting with Lin Chen, clutching the suitcase beside him tightly, and said:
"Little friend, who exactly are you?"
"Never mind, there are some things I can't tell you right now."
"I'm sleepy, I'm going to take a nap."
After saying that, he turned around.
However, Luo Rui'an's wary look confirmed Lin Chen's suspicions.
There must be some secret about Luo Rui'an, which is why he suddenly became wary of Lin Chen.
but……
He is unlikely to be the culprit behind the plane crash.
Thinking of this, Lin Chen stood up and walked towards the cockpit.