One sensitive authorization, proven by the room.

You reach a sensitive site and enter only a name. A one-time challenge arrives on the phone. You approve it on the wearable. A physical event runs between the two devices; both record the same echo from the room; when their observations match, the operation is authorized — APPROVED. It can also be REJECTED. KeyPulse informs the decision; it is not the decision.

FIDO2 and passkeys prove one authenticator and a local user check. Secure Chain keeps that and adds fresh physical co-presence of two independent devices at the instant of the operation. Add it where a physical proof has real value — a high-value transfer, a change of admin rights, an irreversible action.

There is no persistent reusable secret in a database to exfiltrate and no past session to replay. The physical condition has to be met again, every time.

A working end-to-end prototype exists on real hardware — an ESP32-C3 card, an Android app and a backend, with real cryptography. Call it a prototype / R&D demonstrator. Hardware assurance (Secure Element, Secure Boot) is the product trajectory.