Crypto & JWT Playground

Practice cryptography hands-on — AES encryption, RSA key pairs, JWT tokens, hashing, and HMAC. Everything runs in your browser via WebAssembly (Python + cryptography library). No installation, no server, no data leaves your device.

AES Encryption

Encrypt and decrypt data with AES-CBC and AES-GCM. Understand padding, IVs, nonces, and authenticated encryption.

RSA Key Pairs

Generate RSA keys, export PEM, sign & verify messages, encrypt/decrypt, and compute Snowflake-style key fingerprints.

JWT Tokens

Build JWTs from scratch with RS256 signing. Decode, verify, and construct Snowflake key-pair authentication tokens.

Hashing & HMAC

Compare hash algorithms, see the avalanche effect, hash passwords with PBKDF2, and authenticate messages with HMAC.

Or open the full JupyterLab environment with all notebooks:

First load downloads the Python WASM runtime (~30 MB, cached after). Requires a modern browser (Chrome, Edge, Firefox, Safari 18+).
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