Cryptography Cont. Ìtọ́wò (Taster) - Simple encryption/decryption

Let's assume that during the Ibadan-Ijaye war of 1861-1862, Kurumi - the Àrẹ Ọ̀nàkakanfò (Generalissimo) of the Yoruba army wanted to communicate securely with his Balógun (General) at the frontline, how would he do it?

He could of course send an Àrokò to the General detailing the line of action he should take. To make it more interesting, let's assume he chose to send a short note saying: 
Ẹ ṢIGUN NI AFẸMỌJU (Strike at dawn)

To avoid the content of the note being read and comprehended by the adversaries he could use a variant of the Caesar cipher customised for the Yoruba alphabet to mangle the text.

The Caesar cipher (named after Julius Caesar) is a substitution cipher where each letter in the original message (called the plaintext) is replaced with a letter corresponding to a certain number of letters up or down in the alphabet to create the ciphertext (mangled text).

Below is the Yoruba alphabet (Upper case):
A B D E Ẹ F G GB H I J K L M N O Ọ P R S Ṣ T U W Y

If we shift the alphabet by 6 character to the right, we end up with:
S Ṣ T U W Y A B D E Ẹ F G GB H I J K L M N O Ọ P R

Now, A is S, B is Ṣ, D is T etc

So the original message “Ẹ ṢIGUN NI AFẸMỌJU” becomes:
W NEAỌH NE SYWGBJẸỌ

For this to work though, the Generals (Balogun) must have been told beforehand to shift the alphabet by 6 characters.

This is a very simple encryption that can be broken easily but it does suffice as an example here.
Next time we will use Odù Ifá to create a more secure encryption.