Chapter 437 - Cipher

The key to unlocking these materials lay in identifying who each code name represented. With that knowledge, these documents would transform into devastating "black materials"—their release far more lethal than any ledger of "Three Festivals and Two Birthdays" gifts. After all, the difference between an actress adhering to "unspoken rules" and one being raped was the difference between gossip and a criminal case.

Lin Baiguang was convinced that Gou Er couldn't possibly possess a superhuman memory capable of recalling every person behind every code name. There had to be a cross-reference table somewhere—a master cipher linking pseudonyms to real identities.

Yet if Lin Baiguang had reasoned this far, Gou Er surely had as well. As the document sorting drew toward completion and Sun Xiao still hadn't located the crucial roster among the account books, Lin Baiguang's expression darkened. To discover such valuable material and find it unusable—the disappointment was almost unbearable.

"Don't be too disheartened," Mu Min offered. "Perhaps Gou Er memorized it himself. Or he carries the master copy on his person. Besides direct searching, we can employ intelligence analysis to deduce who these code names refer to."

"By cross-referencing the materials, we can generally determine where a person is located, what specific activities they engage in, and who their contacts are. From there, we can make reasonable guesses." She picked up the bribery registry. "Take this 'Old Man of Lanling' mentioned in the final entry—he received payment to intercede with Wu Mingjin on some matter, and it was successfully handled. Clearly, this person enjoys a close and rather extraordinary relationship with Wu Mingjin."

"I'd considered that," Lin Baiguang replied. "But Wu Mingjin has quite a few trusted aides—confirming precisely which one would be difficult. Besides, if it were Assistant Magistrate Wu Ya or an important member of the local gentry interceding, Wu Mingjin would hardly reject them outright."

"Which is why we need to synthesize all the materials. Only then can we deduce the truth."

When they finally finished clearing the box, Lin Baiguang found exactly what he needed: the roster.

Sun Xiao brought it over, and Lin Baiguang's heart leapt. With this document, he would have a firm grip on all the "bezoars and dog treasures" hidden in the bellies of these Qiongzhou Prefecture officials!

He opened it—and his excitement immediately curdled. It was indeed a cross-reference table. Each page was divided into upper and lower columns, the upper containing the person's code name, the lower showing meaningless three-character combinations. Judging by their bizarre construction, these couldn't possibly be actual names.

"Damn! This Gou Er is truly cunning! This must be another layer of cipher!"

Mu Min suspected the same but confessed complete ignorance of cryptography. Through the personnel database, they identified an expert: Zhang Xingpei.

Zhang Xingpei had only recently returned from Guangzhou, where he'd enjoyed excellent hospitality—four or five women in one breath had left him exhausted. Back in Lingao, he desired nothing more than rest and recuperation. But a phone call summoned him to the Political Security Bureau.

On the way, anxiety gnawed at him. Had he done something to wrong the Crossing Group? Could his "lifestyle" issues in Guangzhou have been reported? Surely the Security Bureau didn't concern itself with such matters of the lower body... Unable to puzzle it out, he simply reported for duty.

"Look at these," Lin Baiguang said without preamble. "Is this a cipher?"

Zhang Xingpei harbored a strong interest in cryptography and intelligence studies and had devoted considerable effort to their study. Of course, his knowledge remained at the most basic level. The mention of ciphers alarmed him—his entire framework was Western. He had no conception of what ancient Chinese ciphers might look like.

"This is extremely difficult," he admitted. "I know nothing about ancient Chinese ciphers. The ancients probably wouldn't employ overly complex systems, but without understanding the underlying mechanism, I wouldn't know where to begin."

"Surely the principles are the same?"

"Hard to say." Zhang Xingpei shook his head. "Chinese uses eight hundred common characters, while Western systems use merely a few dozen letters. From a coding perspective, an alphabet is obviously far easier to work with than a logographic script."

This vast difference in writing systems created completely divergent approaches to secret communication. Ancient China relied more heavily on secret slang and argot—jargon passed down orally, fundamentally different from true ciphers. Zhang Xingpei knew a little about such slang, but it bore no resemblance to the document before him.

"Quickly, call Luo Duo! Tell him to research ancient Chinese cryptography materials!"

"It's the middle of the night. Disturbing people at this hour lacks basic civic virtue—" Zhang Xingpei, already irritated at being summoned so late, seized the opportunity to voice his displeasure.

"Don't worry. This 'walking encyclopedia' is definitely still in the Social Work Department office." Lin Baiguang clearly had no interest in civic virtue, and he knew Luo Duo's habits well—the man's greatest joy was research, and the later the hour, the sharper his mind.

But Luo Duo couldn't offer much additional material—at midnight, he couldn't access the Grand Library's computer center for searches. Drawing from his limited memory, Zhang Xingpei learned that ancient Chinese military ciphers fell mainly into two categories. The first was "hidden language," similar to jianghu slang, though the precise methods could no longer be verified.

The second was "word verification"—ziyan. This involved compiling forty items covering situations likely to arise in military communication: "Request Bows," "Request Arrows," "Request Advance," "Request Reinforcements," and so on. The corresponding parties would agree upon a five-character regulated poem containing no repeated characters as the "word verification." When writing a letter, the item number of the matter to be reported would correspond to the Nth character in that poem. By placing a small dot beside that character, the message was conveyed. Even if the letter fell into enemy hands and the method was known, without the master list of item numbers, knowing the poem itself was useless.

"...But this method is primarily for communication. If Gou Er used something similar purely to prevent leaks in his personal records, the approach might be entirely different."

"Fascinating," Zhang Xingpei murmured, falling into deep thought. "Substituting meaning with characters..."

Luo Duo then introduced a cipher invented by Qi Jiguang based on fanqie pronunciation—already quite similar to modern ciphers. But judging from the complexity he described, everyone agreed that Gou Er would never employ something so elaborate. In fact, this cipher had been used only briefly within the Qi Family Army and never spread widely.

Zhang Xingpei took pen in hand and copied the entire account book. One thing was now certain: these nonsensical three-character combinations represented people's names. He examined his copy carefully, and within minutes found a breakthrough.

"I have an idea." He pointed at the characters. "This is a simple substitution method—also known as the Caesar cipher."

"When did Gou Er ever learn about Caesar?"

"I'm not saying he used the actual Caesar cipher, just that the principle is similar." Zhang Xingpei explained: The so-called Caesar cipher simply replaces each letter in the plaintext with a different letter or symbol. According to historical records, Caesar himself replaced each letter with the one three positions ahead.

"That seems unlikely," Luo Duo immediately objected. "How many letters are there? Common Chinese characters number over eight hundred. The character table would be enormous—Gou Er would need to carry a codebook as thick as a telegraph manual."

"I'm not certain how he managed it." Zhang Xingpei shook his head. "But based on probability, I can roughly deduce a few surnames."

His reasoning was simple. Since these were all names, the first character of each three-character combination must represent the surname. And surnames had frequency distributions—just as 'e' appeared most often in English, certain Chinese surnames dominated. Wang, Zhang, Li, Chen were the most common. Though Zhang Xingpei didn't know the exact ranking in the Ming dynasty, he assumed it couldn't differ dramatically from modern times.

"You'll need to account for local variations," Luo Duo reminded him. "In Lingao, Fu is a major surname, and there are many Fujian immigrants, making Lin quite common as well."

"That's the challenge." Zhang Xingpei isolated the most frequently appearing surname characters and studied them repeatedly, but the path forward remained elusive.

"This is bad," he finally admitted. "I have no feel for ancient Chinese texts. Gou Er definitely used a classical book as his codebook—something very common, just as Europeans often used the Bible."

"I think I've identified one." Mu Min suddenly spoke. "The person who interceded with Wu Mingjin for Gou Er's son must be Wang Zhaomin—his private secretary!"

Every gaze turned to her.

"Look—the first character corresponding to 'Old Man of Lanling' is exactly one of the high-frequency surnames Zhang Xingpei identified: Wang, Zhang, Li, Chen. Add Fu and Lin. Now consider: among Wu Mingjin's trusted associates, or those who can speak to him effectively, who matches these surnames? Only Wang Zhaomin!"

"Yes, yes." Lin Baiguang nodded eagerly. Checking against their data, the match seemed increasingly plausible.

"By cross-referencing the bribery registry with our understanding of Lingao's social landscape, we should be able to identify quite a few names—fortunately, we're only dealing with names, which are relatively easier to guess."

Other regions might prove difficult, but the intelligence department had an excellent grasp of Lingao's basic social situation. Soon, they extracted several more names from the clues.

"But relying on guesswork alone limits our accuracy," Mu Min cautioned. "And once we move beyond Lingao, this method becomes unreliable. We still need to find the actual character table."

"Let me work on it slowly," Zhang Xingpei said. "Since we've already confirmed a few characters, we can proceed by elimination. I'll start with the Hundred Family Surnames, the Three Character Classic, and the Thousand Character Classic—any educated person in the Great Ming can recite these from memory."