Greetings, young codebreakers, and secret agents in the making! Are you ready to embark on an exhilarating journey where words become puzzles and messages become mysteries? Today we’ll explore writing secret codes. Writing secret codes is not just a game—it’s a way to communicate in a language known only to you and your trusted allies. Whether you’re passing notes in class, sending secret messages to friends, or simply exploring the art of cryptography, unveiling ancient ciphers, will empower you to become a master of secret communication. So, grab your pencils, don your detective hats, and let’s unravel the secrets of the clandestine world of writing secret codes!

Cryptography is the use of codes and ciphers to keep information secret. Records show that cryptography has been used for thousands of years.

Historically, cryptography methods primarily involved the use of pen and paper encryption or simple mechanical aids. For example, clay tablets found in Mesopotamia dating from 1500 BC had an encrypted recipe for pottery glaze. And Hebrew scholars were using substitution ciphers as far back as 500 or 600 BC.

In modern times, the ability to send encrypted messages has been of vital importance during war efforts. For example, the US recruited and trained Navajo “code talkers” during World War II. These code talkers developed a code in their native Navajo language, aiding the US in its war effort against the axis forces by enabling secret messages to be transmitted.

Codes vs. Ciphers

Cryptography uses both codes and ciphers. But what is the difference?

Codes are based on semantics, or the meaning of language. An example of code used by the Navajo code talkers for the word “plane” is “wo-tah-de-ne-ih.” In contrast to codes, ciphers are based on syntax, or symbols. Ciphers are typically just a set of instructions (an algorithm) for converting one set of symbols (e.g., letters) into another set of symbols (e.g., numbers or pictographs). An example of a simple letter-to-number cipher is A=1, B=2, C=3, etc.

All that being said, while codes and ciphers are different, the terms are often used interchangeably. Morse code, for example, it technically a cipher, not a code. Nonetheless, it is called Morse code, not Morse cipher.

Morse Code—converts letters and numbers into a series of dots and dashes (sometimes called dits and dahs). In Morse code, each dash has a duration that is three times as long as each dot. Each dot or dash within a character is followed by a period of no signal, called a space, equal in duration to the dot.

Morse code is well suited to be communicated through sound using audio tones. It can also be communicated visually using flashing lights. Although the code is not designed to be transmitted in written format, it can be written as well.

The Caesar Shift Cipher—is named after Julius Caesar, as he used this cipher to encrypt messages. However, it isn’t a very difficult cipher to figure out and thus messages sent with this cipher did not stay secret for very long.

With the Caesar Shift cipher, each letter of the alphabet is “shifted” some fixed number. The shift is named a “ROT,” which stands for “rotation.” For example, with a ROT1 shift A becomes B, B becomes C, and so on. With a ROT13 shift, on the other hand, A becomes N, B becomes O, C becomes P, etc. To decode a message sent using the Caesar Shift cipher, the person must be aware what shift has been used.

Codes and ciphers can be fun. There are a lot of “codebreakers” and “cipher-makers” out there on the Internet for you to use and have fun with. Go find them and have fun sending your secret messages!

AIME