A (Brief) History of Encryption


When talking about encryption, it’s important to make the distinction that all modern encryption technology is derived from cryptography. Cryptography, is – at its core – the act of creating and (attempting to) decipher a code. While electronic encryption is relatively new in the grander scheme of things, cryptography is a science that dates back to ancient Greece.

The Greeks were the first society credited with using cryptography in order to hide sensitive data in the form of written word, from the eyes of their enemies, and the general public. They used a very primitive method of cryptography that relied on use of the scytale as a tool to create a transposition cipher (answer key) to decode encrypted messages. The scytale is a cylinder used to wrap parchment around in order to decipher the code. When the two sides communicating used a cylinder of the same thickness, the parchment would display the message when read left to right. When the parchment was unrolled, it would appear as a long, thin piece of parchment with seemingly random numbers and letters. So, while un-rolled it may seem to be compete gibberish, when rolled on to the scytale it would look more like this:


The Greeks weren’t alone in developing primitive cryptography methods. The Romans followed suit by introducing what came to be known as “Caesar’s cipher,” a substitution cipher that involved substituting a letter for another letter shifted further down the alphabet. For example, if the key involved a right shift of three, the letter A would become D, the letter B would be E, and so on.

Other examples that were considered breakthroughs of their time were:

  • The Polybius square: Another cryptographic breakthrough from ancient Greece relies on a 5 x 5 grid that starts with the letter “A” in the top left and “Z” in the bottom right (“I” and “J” share a square). The numbers 1 through 5 appear both horizontally and vertically atop the top row of letters and to the far left. The code relies on giving a number and then locating it on the grid. For example, “Ball” would be 12, 11, 31, 31.
  • Enigma machine: The Enigma machine is a WWII technology known as an electro-mechanical rotor cipher machine. This device looked like an oversized typewriter and allowed operators to type in plaintext, while the machine encrypted the message and sent it to another unit. The receiver writes down the random string of encrypted letters after they lit up on the receiving machine and broke the code after setting up the original pattern from the sender on his machine.
  • Data Encryption Standard: The Data Encryption Standard (DES) was the first modern symmetric key algorithm used for encryption of digital data. Developed in the 1970s at IBM, DES became the Federal Information Processing Standard for the United States in 1977 and became the foundation for which modern encryption technologies were built.