Classical
Caesar Cipher
Shifts each alphabetic character by a fixed offset.
Playground
Change inputs and inspect the transformation
A monoalphabetic substitution where the key is one number.
Output
Ciphertext
OHDUQ FUBSWR
Decrypted
LEARN CRYPTO
Steps
Transformation trace
Normalize key
3 mod 26 => 3
The alphabet has 26 letters, so shifts wrap around.
Encrypt
letter index + shift => OHDUQ FUBSWR
Each letter moves forward by the same offset.
Decrypt
cipher index - shift => LEARN CRYPTO
The inverse shift recovers the original text.