Project · iOS · Education · Free on the App Store
Play with Krypto
Learn how cryptography works by experimenting with it. An interactive lab for students, developers, and curious minds who want the ideas to feel concrete — not abstract.
What you will explore
Classic & modern ciphers
Caesar, Vigenère, Playfair, Rail Fence, XOR, AES-256, and RSA encryption labs with step-by-step explanations.
Hashing & signatures
SHA-256 fingerprints and P-256 digital signatures with calculated verification values you can inspect.
Authentication labs
RSA challenge–response login, TOTP authenticator codes (RFC 6238), and HMAC challenge–response.
Blockchain & cryptocurrency demos
Build chains, try tamper attacks, simulate ledgers, and optionally connect with nearby friends on your local network.
Build your own encryption
Combine reversible steps into custom recipes, test every stage, save, and share the recipe (secrets stay as prompts only).
Calculated values everywhere
See hashes, fingerprints, signatures, and pass/fail reasons — so you understand why verification works or breaks.
Privacy & data
- No account required to use the app.
- Lab content, keys, and saved recipes stay on your device.
- We do not operate a backend that receives your lab data.
- Optional nearby mode uses your local network only (Multipeer Connectivity) — never our servers.
Who it is for
Anyone learning computer science, security fundamentals, or cryptography for the first time — and anyone who wants a safe sandbox to break things on purpose and see what happens.
Availability
Play with Krypto is available free on the App Store for iPhone and iPad (iOS 17+). Advanced labs unlock with a one-time Pro purchase. Support and privacy documentation are below.