Did you guess what the title means? Well, it’s an example of a cipher.
A cipher is a way of encoding your writing so that only someone who knows the trick can read what you’ve said. Ciphers have been used since the Romans. Julius Caesar is said to have developed a system in which each letter of the alphabet is moved 1 or 2 letters to the right, for instance*;
Another well known cipher is Alberti’s disk. It was created by Leon Battista Alberti and uses polyalphabetic substitution. It is created with 2 concentric disks attached to a center pin. The outer disk is stationary and has the conventional alphabet, the inner disk can spin and contains the code that you will be using.
Other famous ciphers include Enigma, the cipher that Germany used in WWII, that was famously broken by Alan Turner in an act that probably cut the war short 2 years, saving millions of soldiers.
Jg zpv ibeo’u opujdfe cz opx, uif ujumf jt tjnqmz nbef cz dpowfsujoh uif mfuufst pg uif ujumf joup uif tzncpmt po upq pg uifn mjlf uijt—Hello=(3””9.**
If you want, you can learn more here.
*Also known as a ROT cipher
**This portion is encoded