Play with Krypto

Explore ciphers, signatures, JWT, and blockchain labs on your iPhone — clear explanations, calculated values, and experiments you can break on purpose.

Play with Krypto is a hands-on cryptography lab for iPhone and iPad. Learn how encryption, hashing, signatures, and authentication really work — by trying them yourself.

Start with classic ciphers, then move into modern tools like AES and RSA. See digital signatures verify exact content. Explore authentication with challenge–response, authenticator codes, HMAC, and JWT tokens. Build a simple blockchain, experiment with a cryptocurrency sandbox, or invent your own encryption recipe.

Every lab is designed for learning: • Step-by-step controls you can change • Calculated values that show why verification succeeds or fails • Safe “break it on purpose” experiments

Educational only — not a wallet, exchange, bank, or payment app. Demo keys and currencies stay on your device for learning.

FREE TO START • Classic ciphers (Caesar, Vigenère, Atbash, Rail Fence) • SHA-256 hashing • Digital signature verification • Blockchain demo

PRO — ONE-TIME UNLOCK (£2.99) • Advanced & modern crypto (AES, RSA, and more) • Authentication labs (RSA login, TOTP, HMAC, JWT) • Cryptocurrency lab (including optional nearby friends mode) • Build your own encryption recipes

No account required. Built by SUBABYTE LTD in the United Kingdom.