My latest book, The Plotting Shed, follows a twelve-year-old spy. Last week I wrote about codes, but how do you make a code? Here are some simple guidelines. Have fun!
Throughout many generations, kids have made codes as a hobby. The messages composed from these have been kept secret, even if they have been intercepted by others, whether they have been written in a diary or sent among friends. Making up a code mostly requires a little bit of knowledge, and a lot of imagination.
Terms used in Cryptography
Code – One word is substituted for another
Cipher – One letter or symbol is substituted.
Many people use the words codes and ciphers interchangeably and they can be combined in order to make messages harder to be read.
Encrypting – Making a cipher/code
Decrypting – Reading the message
Double Encryption – Using both a code and cipher to compose a message
Code Book – Key for deciphering the message. All the symbols and their meanings are written in this book and shared with all recipients.
Steps to Making a Code
- Determine the Direction – Codes can be written left to right, right to left or even top to bottom. Some of the most difficult codes to break have been written diagonally.
- Choose the Number of Symbols – You can either use the same number of symbols as the letters in the alphabet (one symbol for each letter) or one symbol can be used for two or more letters. Doubling up on a symbol will make it harder for anybody to break the code.
- Decide the Writing style – The message can be written in one continuous line or broken up into words.
- Create the Symbols – Characters in your code should be based on the things that have a meaning to you personally.
Tips to Creating a Code
- Long flowing characters are easier to read than short ones.
- Keep all symbols distinct, as blending and joining them will make the code too difficult for the intended reader to decipher.
- Continuous writing styles are the most difficult codes to break. In order to make them readable, however, different symbols can be used to identify a space, as well as frequently used punctuation marks.
- A good hiding place for a key is in a pen that has been taken apart and then put together again.
Types of Codes
Written Codes – The majority of codes are written and have a specific key to decipher them.
Book codes – A book is chosen that all of the recipients are aware of. The message is then written in the form of page number, line number, word number to represent each word.
Spoken codes – Secret languages can be made up and practiced. This means that the participants will all need to memorise each word and how to pronounce it.
Tapped Codes – A different series of taps can be made up to represent each letter.
Cryptography as a hobby can be a fun way to challenge yourself and your imagination, and can even be further developed into an exciting career. Good luck with making your first code!