Code Breaker

That the producers would be interested in Bauer was not a surprise. He is, after all, a mathematician and a foremost expert in cryptology, the study of codes and codebreaking. He is Editor-in-Chief of the journal Cryptologia, author of two books on cryptology: Unsolved! The History and Mystery of the World’s Greatest Ciphers from Ancient Egypt to Online Secret Societies and Secret History: The Story of Cryptology, and former Scholar-in-Residence at the National Security Agency’s Center for Cryptologic History. 

These are impressive credentials, to be sure. And yet, Bauer was at first reluctant to accept the show’s invitation. He feared they wanted him as an expert voice, not as a participant in the search. Bauer was disinterested in a cameo, no matter how prominent.

“I didn’t want to go on the show and kind of be bobbing around through five episodes not making any progress,” Bauer says from his office on campus. “If I was going to take on a challenge like this, I was going to be all in.”

In the end, Bauer accepted, but what transpired was something even he did not anticipate. Bauer leaped headlong into the work. He read everything he could find about the Zodiac. He wanted to get inside Zodiac’s head. His reward was cracking one of the killer’s most notorious unsolved ciphers known as Z340.

“I was trying to figure out how does this man think? What would he do in creating this cipher?” Bauer recalls. “Ultimately, that approach paid off.” 

Not Child’s Play

The mysterious world of codes and ciphers is not child’s play to Bauer. It is the stuff of legend. As he sees it, encryption, or, more accurately cryptanalysis (cracking codes and ciphers), is often the difference between winning and losing on the grandest stages of history. In World War II, military experts now acknowledge that the Allied victories, in both Europe and the Pacific, were not solely due to overwhelming strength, superior strategy, and the Atom Bomb. It came down to cryptanalysis – of two systems, in particular. 

The first and most famous was the German encryption juggernaut, known as Enigma, but even before the war began, Polish mathematicians had broken the cipher. With Poland soon occupied, those Polish cryptanalysts escaped and passed their hard-won knowledge on to codebreakers in England. The British team included Alan Turing, whose effort to crack Enigma was chronicled in the Academy Award-winning film, The Imitation Game. Turing eventually broke Enigma, like Bauer had with Zodiac, by thinking less like a mathematician and more like a psychologist. Each codebreaker got into the mind of his adversary.

The other decisive moment for cryptology came in the earliest days of the war in the Pacific. American codebreakers had secretly solved the Japanese naval code and, using a clever ruse, learned that the Japanese fleet was somewhere near Midway Atoll. In June of 1942, just six months after Pearl Harbor, American dive-bombers descended upon an exposed Japanese fleet. In the coming days, the Americans sunk all four of Japan’s large aircraft carriers. With those crucial ships gone, Japanese superiority in the air and sea vaporized. American victory was only a matter of time.

“Codebreaking made the difference in the Battle of Midway, and Midway made the difference in the Pacific,” Bauer says. “We never lost another battle after that.”

Renewed Interest

Encryption remains a crucial part of society today, but on different fronts. The scads of personal data we carry around in our cellphones are encrypted using techniques that have evolved considerably from simple character-for-character replacement schemes. 

Much of today’s encryption involves complex mathematics and has proven so tough to crack that even experts at the National Security Agency, the Central Intelligence Agency and the FBI have trouble accessing data in cellphones. A standoff between Apple and investigators of the San Bernardino terrorist shooting made national headlines when the tech giant refused to help investigators crack the assailant’s iPhone.

The rising interest in cryptology can be plainly felt on the York campus, Bauer says. Bolstered by a new major in Intelligence Analysis, he is seeing an influx of students to his mathematics courses, Cryptology (MAT391) and History of Codes and Ciphers (MAT107). 

The Cryptology course shows the evolution of modern cryptology. The class explores dozens of systems and how clever attacks broke them, forcing cryptographers to create ever more sophisticated methods. Bauer presents advanced computer encryption schemes, including public key cryptography and the very latest advances in next-gen Quantum cryptography. Throughout the course, the real-world consequences of systems that failed, as well as those that held secure, are detailed.

“I love all aspects of cryptology, not just the mathematics. I love the history. I love that cryptology helped us beat the Nazis and the Japanese, and probably shortened that war by a couple of years,” says Bauer. “It’s getting a lot of kids interested in math again.”

Bauer is quick to point out that the History of Codes and Ciphers class is not ivory tower stuff, but accessible to every student on campus. It is more history than mathematics, he says, and tells a fascinating tale. For students looking forward to careers with the National Security Agency, the Central Intelligence Agency and other groups in the intelligence community, his classes are a perfect fit.

“Craig’s Cryptology class has about 40 students a year, many from non-math majors,” says Associate Professor David Kaplan, Ph.D., coordinator of the mathematics program at York. “It is a really popular elective for Intelligence Analysis majors and a key part of our cybersecurity management constellation of classes.” 

“It’s also an absolute blast to teach,” Bauer adds. 

Writing leads, code follows

Cryptography has been around almost as long as written language. Wherever there are words written down, people will want to keep secrets.

“In almost all cultures, as soon as writing develops, cryptography soon follows,” Bauer says.

Most often, ciphers protect valuable information, from those military secrets in World War II to financial and medical data to who really owns that batch of bitcoins. Other times, ciphers are devised just for fun. The Nobel-winning physicist Richard Feynman is famous for cracking some of the laws of physics, as well as taking on still-unsolved ciphers made by a friend of his that proved too hard to crack. The British composer Edward Elgar also left behind an unsolved cipher, one that he composed himself. 

Sometimes, however, there is a more insidious aspect to ciphers. Serial killers love to encode their messages, perhaps as a not-so-subtle assertion of intellectual superiority. Whatever the reasons that drove Zodiac to encipher, his Z340 note had proved uncrackable for nearly 50 years. Z340 – so named because it was written by Zodiac and included 340 characters – had gained renown among Zodiac hunters and cryptologists alike because the killer claimed it would reveal his true identity.

Why was Z340 unsolved? Bauer chalks it up to Zodiac’s personal proclivities. The first was plain poor spelling, possibly intentionally so. Misspelling is a curse to cryptanalysts because codebreaking is based on the likelihood that certain letters will appear in a text. It is simple probability, says Bauer. In English, for instance, the E is the most common letter. The cryptanalyst’s first step is to insert E for the most frequently used letter in a cipher, a T for the second most, and so forth. The codebreaker tries to complete other words by guessing and then substituting those letters elsewhere in the cipher. 

“Every correct guess helps solve other parts of the puzzle,” Bauer says.

The second proclivity was Zodiac’s preference for relatively short ciphers, which lower the odds that probabilistic approaches will succeed. A shorter cipher might have a similar number of Ws as Es, for instance, making substitute-and-guess approaches difficult. 

Last, Zodiac threw an additional wrench in the works. Sometimes he didn’t encrypt at all, leading codebreakers to substitute when no substitution was required.

Weighing heavily in the cryptanalysts’ favor, however, is psychology. Getting to know how the encipherer thinks is, in many ways, more powerful than math, Bauer says. Zodiac’s first cipher was solved by a husband-and-wife team when the wife correctly predicted that a narcissist like Zodiac would likely start his note with the personal pronoun “I” and would use “kill” at least once. Both hunches proved to be correct.

Bauer’s Z340 solution is not 340 letters long – a good section remains unsolved. Bauer thinks it is likely gibberish used to distort the statistics cryptanalysts depend on. As for revealing his name, the killer got in one final torment for his pursuers, falsely declaring himself to be, “RICHARD M NIKSON.” 

The cruel bait-and-switch left Bauer more determined than ever. “Each time an unknown person communicates in writing, he reveals something of himself,” Bauer says. “Maybe we can find a suspect who misspelled Nixon the same way. That could break the case open.”

Whether that day comes is yet to be seen, but Bauer is riding high on a wave of attention that includes his prominent role in a compelling crime documentary, a journal to edit, a new book in print on unsolved ciphers, and two popular courses to teach.

written by Andrew Myers