Cryptography

Cipher machines were used to make cryptography. It was used to write secret codes. Many people used these during wars to send messages.
This is how a cipher machine looked like when it was used in World War II for encryption of very high-level general staff messages: It had many levers, pulleys, and other stuff like that. If you want to see the picture and other pictures of cipher machines, go to wikipedia. org.
Then, type in cryptography. Ok, bye! That's it!