Caesar Cipher

The simplest cipher (and one of the oldest) the Caesar shift is named after Julius Caesar.

The month of July is named after Julius, and he also has his own salad, method of delivering babies and now -- if you want the complete set -- here is the code as well!

Before explaining the dazzling mechanisms of the Caesar-Cipher, we need to define a few terms.

Code-making is known as "cryptography" and code-breaking is known as "cryptanalysis". (Although code-breaking is a much cooler term).

In any code-breaking scenario you have two possible versions of a message: the encoded form, which is known as the "Cipher Text" and the original, un-encoded form, which is called the "Plain Text".

How does the famous Caesar Cipher work?

Take your plain text message, e.g.

We attack at dawn!

And go through each letter of the message, replacing it with a different letter, according to this very clever translation table....

ABCDEFGHIJKLMNOPQRSTUVWXYZ
BCDEFGHIJKLMNOPQRSTUVWXYZA

Okay, let's do this. "We attack at dawn!" The first letter is 'W'. Let's look in our translation table.

ABCDEFGHIJKLMNOPQRSTUVWXYZ
BCDEFGHIJKLMNOPQRSTUVWXYZA
Tb xqqxzh xq axtk!
We attack at dawn!

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