Chapter 227: The Code

Knowing who the codenames referred to was the key. With that knowledge, these materials would become undeniable proof of corruption, far more damaging than a simple ledger of “gifts for festivals and birthdays.” Just as an actress’s “unspoken rules” affair is entertainment gossip, her rape is a criminal case.

Lin Baiguang believed it was impossible for Gou Er to have a superhuman memory for every codename. There had to be a reference list, a key, linking the codes to the real names.

However, if Lin Baiguang could think of this, so could Gou Er. As the organization of the materials neared its end, Sun Xiao still hadn’t found the most valuable item: the name roster. Lin Baiguang’s expression soured. Discovering such valuable intelligence only to find it unusable was incredibly frustrating.

“Don’t be too disappointed,” Mu Min comforted him. “It’s possible Gou Er memorized it all, or maybe he keeps the roster on his person. Besides using direct evidence, we can also use intelligence analysis to figure out who the codenames refer to.”

“By cross-referencing the materials, we can generally determine a person’s location, their role, and the people they associate with. From there, we can make an educated guess,” Mu Min explained, picking up the bribery ledger. “The last entry in this book mentions ‘Lanling Weng.’ He accepted money to speak to Wu Mingjin on someone’s behalf, and he succeeded. Clearly, this person is a close and trusted associate of Wu Mingjin.”

“I thought of that too,” Lin Baiguang said. “But Wu Mingjin has several confidants. It’s hard to be certain who it is. Besides, if it were County Magistrate Wu Ya or an influential local gentleman who spoke to him, he couldn’t easily refuse them on the spot.”

“That’s why we need to look at all the materials together. That will help us deduce the truth.”

As they sorted through the last of the boxes, they finally found what Lin Baiguang was looking for: the roster.

When Sun Xiao brought it over, Lin Baiguang was ecstatic. With this, he would have a firm grasp on the dirty secrets of Qiongzhou’s officialdom!

He opened it, only to feel his excitement turn to ice. It was a reference list, but not the kind he expected. Each page was divided into two columns. The top column listed the codenames, while the bottom one contained bizarre, meaningless three-character combinations that couldn’t possibly be human names.

“Damn it, this Gou Er is a crafty devil! This must be another layer of code!”

Mu Min suspected it was some form of cipher, but she knew nothing about the subject. A quick search of the personnel database on the computer led them to their cryptography expert: Zhang Xingpei.

Zhang Xingpei had just returned from Guangzhou and was enjoying a well-deserved vacation. In Guangzhou, he had been treated exceptionally well, indulging himself with four or five women to the point of exhaustion. Upon returning to Lingao, he had been planning a period of rest and recuperation. But a single phone call summoned him to the Political Security Directorate.

Anxious, Zhang Xingpei racked his brain, wondering if he had done anything to betray the transmigrators’ cause. Had his “lifestyle issues” in Guangzhou been reported? But the Political Security Directorate didn’t usually concern itself with matters of the lower body… Unable to think of any reason, he had no choice but to report as ordered.

“Take a look at this. Is it a code?” Lin Baiguang asked, getting straight to the point.

Zhang Xingpei had a keen interest in cryptography and intelligence, having studied them on his own. Of course, his knowledge was at a very basic, introductory level. The mention of codes startled him—all the examples he had studied were Western. He had no idea what ancient Chinese cryptography looked like.

“This is very difficult. I know nothing about ancient Chinese ciphers…” Zhang Xingpei hesitated. “The ancients probably wouldn’t have used anything too complex, but without knowing the system, it’s hard to know where to begin.”

“The principles should be the same, right?”

“It’s hard to say,” Zhang Xingpei replied. “Chinese uses eight hundred common characters, while Western systems use a few dozen letters. From an encoding perspective, alphabets are much easier to work with than ideograms.”

The vast difference between Chinese and Western writing systems led to completely different concepts for secret communication. Ancient China relied more on slang and hidden languages. Zhang Xingpei knew a little about these, but they were mostly passed down orally and were a world away from cryptography.

“Quick, call Luo Duo! Have him look up materials on ancient Chinese cryptography!”

“It’s the middle of the night. It’s rude to bother someone at this hour,” Zhang Xingpei grumbled, using the opportunity to vent his own displeasure at being summoned so late.

“Don’t worry, that walking encyclopedia is definitely still in his office at the Social Works Department,” Lin Baiguang said, clearly unconcerned with social etiquette. He was familiar with Luo Duo’s habits—the man’s greatest passion was compiling information, and he was most energetic at night.

But even when summoned, Luo Duo couldn’t provide much more information. It was the middle of the night, and he couldn’t access the Grand Library’s computer center to run a search. From his limited memory, Zhang Xingpei gathered that ancient Chinese military cryptography mainly fell into two categories. One was “hidden language,” similar to the slang used in the martial arts world, but how it was used is no longer clear.

The other was called “character verification.” This involved compiling a list of forty items representing various military situations, such as “requesting bows,” “requesting arrows,” “requesting to advance,” “requesting reinforcements,” and so on. The two communicating parties would agree on a five-character regulated verse poem with no repeated characters to use as a key. To send a message, they would encode the item number corresponding to the situation they were reporting. This number would point to a specific character in the poem. In the written message, a small mark would be placed next to a certain character. Even if the letter fell into enemy hands, and the enemy knew the method, it would be useless without the original list of items.

“…But that method is mainly for communication. If Gou Er was just using this for his own security, it’s hard to say if this is it.”

“So it’s essentially using characters to represent ideas. Interesting, very interesting,” Zhang Xingpei mused, lost in thought.

Next, Luo Duo described a cipher invented by Qi Jiguang based on the Fanqie system of pronunciation. This method was quite similar to modern cryptography, but given its complexity, the group doubted Gou Er would use such a sophisticated system. In fact, this cipher was only used briefly by Qi’s army and never became widespread.

Zhang Xingpei picked up a pen and copied the entire ledger. One thing was certain: these nonsensical three-character words all represented names. He studied the copy carefully. A few minutes later, he found a breakthrough.

“I think I’ve got something,” Zhang Xingpei said, pointing to the words. “This is a simple substitution cipher, what’s known as a Caesar cipher.”

“Since when would Gou Er know about Caesar?”

“Of course, I’m not saying he used the Caesar cipher itself, but the principle is similar.” Zhang Xingpei explained that in a Caesar cipher, each letter in the plaintext is replaced by a different letter or symbol. According to historical accounts, Caesar simply replaced each letter with the one three places after it in the alphabet.

“But that seems unlikely,” Luo Duo immediately objected. “There are only so many letters. There are over eight hundred commonly used Chinese characters. How large would that codebook have to be? Gou Er would have to carry around a book as thick as a telegraph codebook.”

“That, I don’t know,” Zhang Xingpei said, shaking his head. “But using probability analysis, I can probably deduce a few of the surnames.”

His reasoning was simple. Since these were all names, the first character of each three-character word had to be a surname. And surnames have a certain frequency of appearance. Just as ‘e’ is the most common letter in English, certain surnames like Wang, Zhang, Li, and Chen are the most common in Chinese. Although Zhang Xingpei didn’t know the exact ranking of surnames in the Ming Dynasty, he figured it wouldn’t be too different from modern times.

“You have to consider the local context,” Luo Duo reminded him. “In Lingao, Fu is a major surname. And with the large population of Fujianese immigrants, Lin is also very common.”

“That’s the difficult part,” Zhang Xingpei said. He isolated the characters that appeared most frequently as the first character of the coded names and stared at them, but couldn’t find a way in.

“This is bad. I have no knowledge of Chinese classics,” Zhang Xingpei said in frustration. “Gou Er must have used an ancient book as his key. And a very common one—just like how Europeans liked to use the Bible as a key for their ciphers.”

“I think I’ve figured one out,” Mu Min suddenly interjected. “The person who spoke to Wu Mingjin on behalf of Gou Er’s son must be Wang Zhaomin—his personal advisor!”

All eyes turned to her.

“Look, the first character of the three-character code corresponding to ‘Lanling Weng’ is one of the most frequent characters Zhang Xingpei identified: Wang, Zhang, Li, Chen, plus Fu and Lin. Now think, who in Wu Mingjin’s inner circle, someone who has his ear, has one of those surnames? There’s only Wang Zhaomin!”

“Excellent, excellent,” Lin Baiguang nodded repeatedly. Looking back at the materials with this in mind, they no longer seemed so alien.

“If we cross-reference his bribery ledger with our intelligence on the social situation in Lingao, we should be able to figure out quite a few names. Luckily, these are just names, which makes them easier to guess.”

While their knowledge of other places was limited, the intelligence department had a thorough understanding of the basic social structure of Lingao. Soon, they managed to identify several more individuals from the clues.

“But just guessing like this has its limits on accuracy, and this method won’t work once we’re outside of Lingao,” Mu Min said. “We still need to find the codebook.”

“Let me take my time with it,” Zhang Xingpei said. “Now that we know a few of the characters, we can start making educated guesses. I’ll start by checking the most common texts: the Hundred Family Surnames, the Three Character Classic, and the Thousand Character Classic. Any literate person in the Ming Dynasty would know these by heart.”