Classical
Substitution Cipher
Maps each plaintext letter to another fixed letter.
Playground
Change inputs and inspect the transformation
The key is a shuffled alphabet, often derived from a keyword in this demo.
Output
Ciphertext
KDLRN BRYPTO
Decrypted
LEARN CRYPTO
Steps
Transformation trace
Build alphabet
keyword = LAB => LABCDEFGHIJKMNOPQRSTUVWXYZ
The keyword starts the alphabet, then unused letters fill the rest.
Encrypt
A-Z -> keyword alphabet => KDLRN BRYPTO
Each plaintext letter maps to one fixed ciphertext letter.
Decrypt
keyword alphabet -> A-Z => LEARN CRYPTO
The inverse mapping recovers the plaintext.