Pendulum Key Cipher
The Pendulum Key Cipher is a custom text encryption tool created by me. It transforms ordinary messages into encoded text using a private key-based process designed for puzzles, creative writing, and hidden messages.
Enter your message, choose a key, select a starting direction, and encrypt or decrypt your text directly on this page. The same settings must be used to correctly unlock the message.
This tool runs in your browser and is intended for creative and educational use.
Pendulum Key Cipher —
Encrypt & Decrypt
Single-file · Client-side · ASCII A–Z only
Invented by Thaddeus Mitchell.
Example patterns. Only digits 1–9 allowed.
Start side
Right starts with positive shifts. Left starts with negative shifts.
Creates a random digit key using digits 1–9.
Input
Only letters A–Z/a–z are shifted; other characters are left unchanged.
Output
Running self-test…