The Tree of Knowledge Daniel Miller (best android ereader TXT) 📖

It is impractical and expensive. Now I have to deal with the police, the media, and several other nuisances that I have zero tolerance for.”

“I know. I’ll fix this.”

“You better, or the security guard won’t be the only dead body I’ll be dealing with this week.”

Chapter 5

“What do we do now?” asked Ying, still carrying the smile that had been tattooed on her face since news of the case had arrived.

Ying Koh had lived most of her life in Singapore and was the youngest child in her family, coming after four brothers. Being both the youngest and the only girl, Ying endlessly fought to be included in her siblings’ activities. Unfortunately, from her first days, the round-faced girl was plagued by multiple ailments that served as a physical and emotional barrier to her inclusion. As a child, she suffered from an intense form of scoliosis, which required her to wear a large plastic brace around her torso eight hours a day. The stress on her back caused her to walk on her tiptoes, which required additional braces around her ankles and calves. Her body, enveloped in braces, gave Ying the appearance of a robot-person, an image that caused both her parents and her siblings much agony and shame. The physical threat of her four protective brothers prevented any of the schoolchildren from teasing her, but the sense of alienation, exclusion, and pity that hung over her during her formative years exceeded any physical pain that bullying could have inflicted. This sense of isolation was exacerbated by Ying’s intelligence. Her ability to calculate complex mathematical calculations in her head, and her participation in international math competitions, confirmed the feeling among her classmates that Ying was somehow different.

So it was with great joy that at the age of seventeen Ying kissed her parents and brothers goodbye and fled to America for college. As she journeyed on the epic plane flight from Singapore to the United States, for the first time she understood the phrase “land of opportunity.” Not in the traditional economic sense, but in a spiritual and emotional sense. Coming to this new land meant that Ying could remake herself. No longer would she be the brace-ridden girl that people looked at with sorrow even after the braces were gone. She would be Ying, the smiley-faced, intelligent, joyful woman that she had always been but no one could see. It was this woman, imbued with optimism and adventure, who sat bright-eyed and grinning in Professor Puddles’s office, soaking up the exciting and terrifying details of the police investigation into which she had just been thrust.

Professor Puddles raised an eyebrow and shook his head at the smiling Ying. “We aren’t going to do anything. You are going to the lecture hall to inform the class that we’ll resume our session tomorrow, and I am going to see if I can break down this cipher.”

“Oh, come on,” implored Ying, her big brown eyes blinking furiously. “You know that it’s probably some type of Caesar cipher, and we’ll be able to do it much faster together than if you do it on your own.”

When she smiled, her cheeks formed two shiny round balls that kept her thick-rimmed glasses from sliding down her undersized nose.

Albert hated to admit it, but Ying was right. Ciphers dated back to the Roman Empire. The Caesar cipher took its name from the emperor Julius Caesar, who used a basic substitution cipher in which each letter of the alphabet was substituted with the letter three places down in the alphabet. For example, the letter A would be replaced with the letter D, the letter B with the letter E, and so on. While the Caesar cipher was relatively rudimentary, it proved extremely effective in its day because the vast majority of the known world was illiterate, and knowledge of linguistics and code-breaking was in its infancy.

While Caesar ciphers served their purposes during the time of the Roman Empire, their simple construction eventually proved too vulnerable for military use. In the ninth century, al-Kindi, an Arab linguist, published a tome on deciphering codes, which introduced the concept of frequency analysis. Using the Koran as his inspiration, al-Kindi documented the frequency of occurrence of each letter in the Arabic language. He discovered that certain letters occurred with much greater frequency than others. The power of this discovery lay in the fact that, for the first time, cryptographers could look at a given cipher and, by identifying symbols that occurred with greater frequency, begin to crack the code. Linguists in other countries soon discovered that these differences in the distribution of letters existed in all languages, thus signaling the death of the Caesar cipher in serious communications.

In 1553, the Vigenère cipher was created to address the weaknesses attributed to the Caesar cipher. In an ironic twist of history, what is now known as the Vigenère cipher was created by an Italian cryptologist named Giovan Battista Bellaso in 1553, but later misattributed to Vigenère, who had developed an even stronger cipher that built on Bellaso’s work. The Vigenère cipher used a Caesar cipher, but instead of a constant substitution shift such as three letters to the right, the shift changed at each position according to a keyword. If the keyword was as long as the text of the message itself, then the code was considered unbreakable. However, in practice, due to the difficulty of remembering lengthy keywords, shorter keywords were often used, making the cipher vulnerable to advanced cryptography. In fact, during the Civil War, the Confederacy regularly used a Vigenère cipher with the key “Complete Victory,” which was eventually cracked by the Union.

Albert prayed that the cipher that lay before them was not a Vigenère. He removed his glasses and massaged the bridge of his nose. “OK, Ying, go tell the class that we’re done for the day and that we will resume tomorrow.”

“Yaaaaay,” Ying exclaimed as she scampered out the office door.

“Tell them to finish the first