Codes require a codebook. Ciphers do not.
Freemason’s Cipher or Masonic Cipher
The Freemason’s Cipher has been around a long time. It was used in the American Civil War to send secret messages. It is also sometimes called the Pigpen Cipher. Read more history here: http://www.wondersandmarvels.com/2012/12/prying-open-the-pigpen-cipher-2.html. And try an interactive online here: http://crypto.interactive-maths.com/pigpen-cipher.html.
Until the early 1920s, radio transmissions were in Morse Code. Three things about Morse Code:
- Dots and dashes make it a binary code like the 0’s and 1’s used in electronics.
- Each letter has a signal based on its frequency in English. The code tree begins with E with one dot, and T with one dash. Then I is represented by two dots, A by a dot and dash, N with a dash and dot, M with two dashes, and so on.
- Morse Code Codebooks were used to lower the cost of sending telegrams, or to keep the contents a secret. Instead of sending a whole phrase or sentence, a single word could be used.
If you want to hear a message in Morse Code, the Morse Code translator at http://morsecode.scphillips.com/translator.html is a great place to visit. You can type in a message, translate it to Morse Code, and play it.