Hello World by Caesar Cipher

The Caesar Cipher is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter a fixed number of positions down the alphabet. The method is named after Julius Caesar, who used it in his private correspondence.

How It Works

To encrypt a message, each letter in the plaintext is shifted a certain number of places down the alphabet. For example, with a shift of 3:

• A becomes D
• B becomes E
• C becomes F
• ...
• X becomes A
• Y becomes B
• Z becomes C

Non-alphabetic characters are not changed.

Decryption

Decryption is performed by shifting letters in the opposite direction. With a shift of 3, for example:

• D becomes A
• E becomes B
• F becomes C
• ...
• A becomes X
• B becomes Y
• C becomes Z

Non-alphabetic characters remain unchanged.

Example

Let's take the message "Hello, World!" and encrypt it using a shift of 3.

Encryption

Original: Hello, World!

1. H shifts to K
2. e shifts to h
3. l shifts to o
4. l shifts to o
5. o shifts to r
6. , remains ,
7. (space) remains (space)
8. W shifts to Z
9. o shifts to r
10. r shifts to u
11. l shifts to o
12. d shifts to g
13. ! remains !

Encrypted: Khoor, Zruog!

Decryption

To decrypt the message "Khoor, Zruog!" with a shift of 3:

1. K shifts to H
2. h shifts to e
3. o shifts to l
4. o shifts to l
5. r shifts to o
6. , remains ,
7. (space) remains (space)
8. Z shifts to W
9. r shifts to o
10. u shifts to r
11. o shifts to l
12. g shifts to d
13. ! remains !

Decrypted: Hello, World!

Usage

The Caesar Cipher can be implemented in various programming languages. The key aspect is to ensure that the shifting logic correctly handles both encryption and decryption, and that non-alphabetic characters are preserved in their original form.