Security / Interactive lab
Cryptography playground
Try real cryptographic primitives without sending your messages or generated keys to ZombieMutex. The replay scenario is explicitly illustrative.
Change the message. Inspect the guarantee.
SHA-256, HMAC and AES-GCM use the browser Web Crypto API with freshly generated demo keys. Replay is a deliberately synthetic model, not a server verifier. Do not paste real secrets.
These algorithms do not establish user identity, object authorization or resistance to compromised clients. Learn the server checks in the existing replay lab.