APSIL -Chapter 63 The Thousand Character Classic and Ciphers

The moment the side gate opened, Zhu Ying immediately pulled Zhang Shou inside.

Standing there with a face as black as the bottom of a wok, Ge Yong barked the instant he saw them.

“Passing by my door once without entering, then doing it again, and this time you even used my name to give away a pile of books! You talked so grandly too. I used to think you were an honest, sincere boy… You’re trying to infuriate this old man!”

Seeing Ge Yong on the verge of exploding, Zhang Shou noticed an imposing elderly gentleman beside him studying him with interest. He stopped Zhu Ying, who was about to explain on his behalf, stepped forward, and bowed deeply.

“Teacher, although I acted on my own when I distributed those books in your name, I did not do it impulsively. I considered it carefully.”

He repeated the reasoning he had used earlier to persuade Zhu Ying not to drive the crowd away. As Ge Yong’s expression gradually softened, he continued.

“Even if my guess was wrong—even if not everyone outside truly possesses talent in mathematics—as long as a few of them really do, then driving them away simply because I couldn’t tolerate their insults would only damage your reputation as the Grandmaster of Mathematics.”

“The dozens of books all came from Lu Sanlang’s bookshop. Their printing cost is negligible. But if they end up in the hands of people with genuine mathematical talent, they could become guiding lights.”

“If only ten people… no, even five… no, even three of them devote themselves to studying mathematics because of these books, then the discipline you have dedicated your entire life to will no longer stand alone.”

“I did overstep my bounds. Please forgive me, Teacher.”

With Zhang Shou respectfully calling him “Teacher” at every turn—and offering such heartfelt reasoning—even Ge Yong, who had merely intended to put on a show of anger, found himself deeply moved.

He suddenly wanted to turn to his old friend and shout:

Look at the broad-minded disciple this old man accepted! They slandered him, and he’s still thinking about nurturing talent!

Unfortunately for him, Zhu Ying beat him to it.

“Grandpa Ge, Grandpa Qi, I originally wanted to chase all those troublemakers away. I even wanted people to block off both ends of the street, record everyone’s names, and report them to His Majesty for violating the prohibition against submitting recommendation manuscripts!”

“It was A-Shou who stopped me.”

“Now that I’ve heard his explanation, I’m so glad he did. He’s broad-minded and thought everything through…”

“Hmph!”

Ge Yong finally found the excuse he needed to climb down gracefully.

“Who doesn’t know your temper, Yingying? Besides him, no one could have talked you out of it!”

Then he turned kindly toward Zhang Shou.

“In the future, be a little more careful. I’m easygoing. If you’d pulled this stunt using Old Qi’s or Old Chu’s name, they’d have expelled you from the sect on the spot.”

Qi Jingshan, who had remained silent all this time, finally laughed.

“Fine, fine. You’re the greatest. Your disciple is better than mine. Satisfied?”

Before Ge Yong could flare up again, Qi Jingshan smiled warmly at Zhang Shou.

“Your handling of today’s farce was excellent.”

“I never imagined you’d not only persuade hot-tempered Yingying to hold back, but also resolve the matter through such a gentle, tactful approach.”

“As for passing by Ge Manor twice without entering…”

He glanced at Ge Yong with amusement.

“Your teacher is only scolding you with his mouth. Don’t take it to heart.”

Ge Yong opened his mouth, intending to protest that he had genuinely been angry.

But maintaining his lofty image was more important.

With a snort, he forcibly changed the subject.

“Of course the brat has his good points.”

“The servants in my household are all deaf and mute.”

“When you and Old Chu’s disciples first came here, every one of you looked like you suspected I was hiding some grand conspiracy.”

“Hmph!”

“They’re all old palace eunuchs left behind by Emperor Ruizong.”

“The Empress Dowager personally sent them to me.”

“They all wanted to follow the late emperor into death. I kept them instead so they could still make themselves useful.”

Then he lifted his chin.

“You mentioned earlier… using mathematics to create… what did you call it? A cipher?”

“Interesting.”

“Explain it properly to us two old fossils.”

“Oh—and I still haven’t asked you about that so-called new book of yours. You suddenly produced another one behind my back!”

Before anyone else could react, Ge Yong had already dragged Zhang Shou straight toward the study.

Zhu Ying stood there dumbfounded for a moment before shouting after them,

“Grandpa Ge! A-Shou still has to visit my grandmother later! Don’t keep him here all day solving math problems!”

She still vividly remembered how Ge Yong had once detained one of his disciples—then the Minister of Revenue—for an entire night over a single mathematical problem, nearly causing him to miss court the next morning.

Inside the study, Zhang Shou began explaining.

“In ancient times, urgent military intelligence was first conveyed through physical objects.”

“For example, tally sticks of different lengths represented different meanings. At most, they could express several or perhaps a dozen messages.”

“But as more specific information became necessary, letters were often divided into three sections and entrusted to different messengers.”

“During the Tang Dynasty, people commonly used character-splitting techniques to conceal messages. The drawback was that there were too many different ways to split characters.”

“By the Song Dynasty, the Essentials of Military Classics even included a chapter prescribing specific verses that could represent over forty kinds of battlefield information.”

He casually picked up a copy of the Thousand Character Classic.

“But if we introduce mathematics…”

“We can use the Thousand Character Classic as a codebook.”

“Every character is assigned a number according to its position—from one to one thousand.”

“For example…”

“If we want to transmit the phrase ‘Yellow, Mother, Passed Away,’ we simply look up the three corresponding numbers and write those numbers down.”

“That alone becomes a coded message.”

“Of course…”

“That’s only the simplest version.”

Smiling, Zhang Shou wrote on paper:

f(x) = 3x + 1

“A slightly more advanced method is to take the numerical values of those three characters…”

“…apply this mathematical formula…”

“…then convert the resulting numbers back into characters before writing the message.”

“As long as the recipient knows the formula…”

“…they can easily reverse the calculation and recover the original text.”

Facing two true masters of mathematics—while quietly ignoring the ever-curious Zhu Ying peeking over their shoulders—Zhang Shou proceeded to write formula after formula, ranging from simple to increasingly complex.

As expected, Ge Yong immediately immersed himself in calculations.

He showed not the slightest sign of encountering functions for the first time.

Watching him derive results with growing excitement, Zhang Shou instantly knew his teacher had already studied the recently published volume on functions.

Nor was Ge Yong alone.

Qi Jingshan beside him also joined the calculations with practiced ease, occasionally offering suggestions of his own.

Clearly, he had thoroughly read the work as well.

Zhang Shou couldn’t help sighing inwardly.

For mathematical grandmasters like them, once they understand the underlying principles, they can infer countless other applications with ease.

At that moment, however, he noticed Zhu Ying glaring at him impatiently.

The message in her eyes was obvious:

Hurry up! We still have to visit my family!

Afraid Ge Yong might begin questioning him about the origins of all those books, Zhang Shou quickly changed the subject with a smile.

“Teacher.”

“This is my first visit to the capital.”

“In a while, I’ll accompany Yingying to pay my respects to the Grand Madam.”

“But elegant gifts are difficult to prepare on such short notice.”

“Would you be willing to give me one of your calligraphy pieces?”

Ge Yong was already lost in thought, wondering whether functions had still more practical applications.

Without even raising his head, he waved impatiently.

“Over there on the desk.”

“Take whatever you like.”

“It’s only calligraphy and paintings.”

“I’ve got as many as you want.”

Hearing that Zhang Shou intended to use Ge Yong’s artwork as a gift for her grandmother, Zhu Ying nearly burst out laughing.

Unlike Zhang Shou, she didn’t hesitate in the slightest.

She immediately dragged him over to the desk and began rummaging through the scrolls.

Before long, she found a painting of magnificent blooming peonies.

The more she looked at it, the more she liked it.

Excitedly, she tugged hard on Zhang Shou’s sleeve and pointed eagerly at the scroll.

Zhang Shou couldn’t help laughing.

This is a gift for your grandmother—not for you.

Still…

Remembering just how indulgent the Grand Madam was toward Zhu Ying, he thought it over before finally nodding.

“If you like it that much…”

“Let’s choose this one.”

“Go tell Teacher.”

“Enough, enough!”

Ge Yong waved them away without looking up.

“Stop wasting time.”

“If you’re going back with Yingying to see her grandmother, then go already!”

“If you don’t have anywhere to stay, come back and stay here…”

Before he could finish, Zhu Ying had already grabbed Zhang Shou by the arm and practically dragged him toward the door.

As she hurried away, she shouted over her shoulder, “There’s no need for Grandpa Ge to worry about A-Shou’s accommodations!”

“The Zhao Duke’s residence has plenty of guest rooms!”

What a joke.

If Ge Yong managed to keep hold of Zhang Shou to study mathematics…

There was every chance he wouldn’t let him leave for ten days—or even half a month.