Code Breaker Academy

Shift letters to turn a normal message into ciphertext, then try to crack secret messages written by other agents. All you need is the alphabet.

20 minCaesar cipherEncryptionPattern finding

Cipher machine

Move the key. Every letter slides the same distance.

Your secret message

Shift key+3

Ciphertext

Phhw ph dw wkh oleudub diwhu vfkrro

Nobody can read this without knowing the shift number. That number is the key.

Outer ring: normal alphabet. Inner ring: scrambled alphabet.

Cracker's playground

Slide the shift until real words appear.

Intercepted message 1 of 3

WKH GRJ LV VOHHSLQJ

Your guess shift 0

WKH GRJ LV VOHHSLQJ

Why 25 keys is not enough

This is a Caesar cipher, roughly 2,000 years old. Julius Caesar used a shift of three to hide military messages. Clever for its time, but today it is a toy. A real encryption key is hundreds of digits long, so trying every possibility would take longer than the universe has existed.

Keys to try

25for this cipher

10⁷⁷for a modern key