I’ve got another secret!
The date was May 17, 1975. It was just eight days before my ninth birthday, and the package arrived right on time, based on the eight to twelve-week window required for shipping and handling! I took the box and ran to my room, carefully carrying the package as though it contained fragile antique glass. Cautiously, I opened it. It was a sight to behold! It was my very first Secret Spy Scope pen, fully equipped with a 6‑power wide field magnifier and 30-power full microscope. Between this, my x‑ray glasses, and my specially developed cryptography code that anybody could probably figure out, my spy days were finally underway.
At the age of nine, I was obsessed with 007 stories and Nancy Drew Mysteries. I thought I had the cryptography down pat, and I thought I had created a unique code that nobody could figure out that substituted numbers for letters and vice versa and shifted the alphabet by five letters. It was easy to figure out. And, as a result, the neighborhood kids found a message to my friend Susan, deciphered it, and learned that I had a crush on the boy next door. I was devastated and gave up my aspirations to become a spy early on.
It would only be a short matter of time before I would discover that cryptography and its various forms had been around for thousands of years. One of the first documented forms of cryptography comes from Caesar’s Cipher, where each letter in the alphabet is shifted by three places down the alphabet. It was first used by Julius Caesar and documented in his stories about the Gallic Wars, which I will get to in a bit here.
Even though this mode of cryptography was named after Julius Caesar, cryptography and its various forms had been around for hundreds of years. A method of cryptography is called steganography, and this includes hidden messages. Herodotus recounted this process when the Persian leader, Xerxes, King of Kings, had planned to attack Greece’s Sparta in 480 BCE. Xerxes thought he had a surefire plan of attack, but little did he know that there had been a spy among the Persians. You see, while Xerxes was mobilizing his forces, Demaratus, a Greek ex-pat who was still loyal to his homeland, was sending messages back to Sparta and Athens using two wax tablets, called tabula cevata, to hide the message. Normally, these wax tablets were used in the classroom as writing tablets. Since there were no pencils and erasers, teachers needed a tool that allowed for erasing markings. Thus, in the classroom, teachers used tabula cevata, which were wooden writing tables. The tabula cevata was a wooden tablet with a recessed surface that held colored wax. Teachers and students would write on the wax with a stylus made of bronze or iron. Like an erasure on a pencil, the stylus had a flat end that allowed one to flatten out the wax in order to reuse the wax on the tabula cevata. The tabula cevata wasminimally bound with approximately two to four tablets secured with a clasp.
However, for Demaratus, it was the perfect spy tool. Herodotus wrote that Demaratus would write Xerxes’s plans on the wood and then cover them with wax so that Xerxes’s guards could not see the message. Once the tablets arrived in Greece, they would scrape off the wax to read the messages as they learned Xerxes’s plans for invasion.
Thus, when Xerxes and his Persian troops arrived in Athens, the Greeks enticed the foreign military to Athen’s shoreline, the Bay of Salamis. Xerxes, thinking he had trapped the Greeks, kept moving in on the bay, unaware that his opponent was preparing to battle. Once one of his ships, the Artemisia, arrived, it was surrounded by Greek troops, who proceeded to take down the entire Persian army.
Steganography was also used in China, as messages were written on fine silk pieces, crumbled into a tiny ball, and then covered in wax. In order to conceal them until they got to their destination, messengers would swallow the ball of wax. I do not know about you, but I would hate to be on the receiving end of that message!
Though steganography is similar to cryptography in that it hides a message, cryptography has a useful method of scrambling the message. If it is found, it cannot be deciphered. Back to Caesar’s shift, his letters first were translated from Roman to Greek and then were shifted three letters up so that his cipher alphabet began with D.
One of the first documented times of Caesar’s cipher was when Julius Caesar was sending messages to his long longtime friend and trusted advisor the Roman Senator Cicero. Caesar was attempting to take down the Roman Empire. He had already proclaimed himself as Rome’s dictator, and the Roman senate was not happy about this. During Caesar’s attempt to take down the Roman Empire, he was sending encrypted messages to Cicero. The message was encrypted so that the Roman letters were replaced with Greek letters, and the entire alphabet was shifted.
The messenger was supposed to deliver the message to Cicero. However, he was instructed that if he could not approach the encampment where Cicero was, the messenger was to hurl the spear with the letter fastened to it into the entrenchment of the camp. Instead, the messenger hurled the spear at the entrenchment where Cicero was, and it stuck in the tower for three days until a guard noticed it. Thus, throughout the Gallic Wars, Caesar continued to use this form of cryptography to communicate with his advisors and army. His methods and forms of communication proved to be useful as he won the Gallic wars.
The Gallic wars is one of many instances where cryptography has been useful in combat. On the morning of February 19, 1945, United States Marines entered the shore of Iwo Jima’s island. This planned attack lasted for five weeks. However, the advancements they made on this island would not have been possible if it was not for Navajo code talkers. The Navajos have a unique language that has no association with European or Asian languages. As a result, they created an unbreakable code that allowed for effective communication within our military.
Even today, internet platforms are secure through public key cryptography. Public key cryptography was introduced by Stanford engineer Martin Hellman, Whitfield Diffie, and Ralph Merkle. Public key cryptography is a process that uses two keys, a private key that is used to encrypt, decrypt, and digitally sign files, and a public key that is used to encrypt and verify digital signatures. Before these brilliant cryptographers first came up with this concept, encryption and decryption were symmetrical and were the same.
Cryptography has evolved in such a distinctive way that we can now use it for cryptocurrency, authentication, privacy, and to deter recent advancements in quantum code-breaking.
So today, we are faced with the challenge of making completely unbreakable encryption. Possibly we are jinxing the word Unbreakable by saying that encryption can be unbreakable. However, today, scientists are currently utilizing key distribution techniques derived from quantum computing. They are creating keys out of photons to produce unbreakable encryption.
The following video is a TED Talk given by John Prisco, the CEO of Quantum Exchange. He goes into how to make unbreakable encryption.
It is insanely exciting to see how far we have come in cryptography and encryption. Moreover, if we can create keys out of photons, I honestly cannot think of how we could advance further on this level of quantum computing. As for me, my head is always in the past, learning the history of stuff. When I learn about the advancements that we are making in cryptography, it just re-instills my faith in the power of science and mathematics and our human intellect that we can create a world that, at one time, was utterly unimaginable. With the exception of history, that is the power of math and science. Until next week, carpe diem!