Answer:
It is called The Atbash Cipher
Step-by-step explanation:
The Atbash cipher also known as Atbash code is a monoalphabetic substitution concept whereby the first letter of an alphabet system is replaced by the last letter. Take for example, in the English alphabet system, letter A would be written as "Z", letter B as "Y" while letter C becomes "X". The purpose of using Atbash is to facilitate secrecy in words or hide real words from people who don't know about Atbash. For example, not everyone knows that "ilhvh" is an Atbash code that means "roses".