Caesar
A single shift value moves every letter around the alphabet. It is fast to understand and easy to break.
KEY = SHIFTClassic cryptography, made legible
Turn a message
into a method.
Explore three foundational ciphers through one focused workspace. Choose a path, set a key, and see the transformation happen in your browser.
Open the workspacePLAINTEXTMEET AT NINE
OUTPUTPHHW DW QLQH
01 / INPUT
02 / TRANSFORM
Workbench
Build your transformation
Everything runs locally in this tab.
Nothing is uploaded.
01Choose a pathEncrypt or decrypt
02Choose a cipherPick your method
03Run the methodRead your result
Operation
What do you want to do?
Cipher model
Select a classic method to use.
Result
Your transformed message
✦
Your result will appear here.
Set a key and message above, then run the method.Quick reference
Three ways to think about a key
A compact guide to the
models in this workspace.
Playfair
A keyword creates a 5×5 square. Two letters at a time are transformed using their shared row, column, or rectangle.
KEY = WORDHill
A matrix turns letter values into vectors. The matrix must have an inverse modulo 26 to decrypt.
KEY = MATRIX