Answer:
Encryption is the process of encoding a message or information in a way that only authorized parties can access it.
During the Boer Wars and WWII, different types of encryption techniques were used, mostly to protect critical and non-critical information about combat tactics and secrets.
During the Boer Wars, the system used was the Playfair cipher, a manual symmetric encryption with a reasonably fast way of use because it did not require any special equipment, only a pencil, and some paper. It was very effective that technique because by the time the message was decoded the information was old.
For the WWII better encryption systems were used because of the importance of the conflict had. The Germans developed a system called Enigma while the Japanese had a similar cipher system named Purple by the US Army.
It was very effective those techniques but after the allies broke them, it allows to decode invaluable sources of military intelligence.
I hope this answer helps you.