Visual one-time pad

  1. Using your mouse, finger, or the arrow keys ↑ ↓ ← →, slide the black encryption key around to decrypt each of the two ciphertexts.
  2. When you've got it right, the secret message will suddenly become visible.
  3. You can also slide the ciphertexts around to see why it's called the "one-time pad" and how things go wrong when you encrypt two messages with the same key.
  4. Learn more about one-time pads and visual cryptography on Wikipedia.
Ciphertext 1
Ciphertext 2
Encryption Key