Type a message and watch the oldest ciphers work on it, letter by letter: Julius Caesar's single shift, the frequency-counting attack that breaks it, and the keyword cipher that resisted for three centuries. Every addition is shown with your numbers. You drive: advance one card at a time with Next — or press ▶ Play to run it start to finish.
Letters only (spaces and punctuation are dropped — the classical convention). Up to 40 letters; the key must be shorter than the message. Advance with next →| (or the → key); replay ↩ reruns a card; ← steps back; space plays/pauses.