Monoalphabetic Cipher

A substitution cipher where each letter is replaced with another letter from a scrambled alphabet. The key is a 26-letter permutation of the alphabet.

Input Text

Substitution Key (26 letters)

How it works:

•Each letter of the alphabet is mapped to a unique substitute letter
•The key must contain exactly 26 unique letters
•Example: If key is "QWERTY...", then A→Q, B→W, C→E, etc.
•More secure than Caesar cipher due to larger key space