Sphragis
Exploring sign-in with a key that stays on your device.
Experimental. Not available for public use. Hardware-backed security and browser sign-in are not yet proven.
Sphragis is an experimental authenticator project. Its design calls for authentication keys that cannot be exported from the device and sign-in that requires the person to be present. These are requirements, not verified security guarantees.
An intended sign-in
You would confirm a sign-in on your device rather than send its private authentication key elsewhere. A complete device-to-browser sign-in has not been demonstrated in the evidence reviewed for this page.
What the early work shows
A recorded test used simulated USB communication. It does not establish a working hardware authenticator, browser compatibility or certification. No device is offered for sale here.