Sticky-note passwords
Operators on rotating shifts share one account for the apps on each industrial PC (IPC), and the password is often taped to the monitor. When a setting changes or a defect slips through, nobody can say who was at the machine.
Pilot program open · Japan · Thailand
Hardware Root of Trust for Physical AI & Industrial Zero Trust
Give every operator their own FIDO2 security key for about $15. Operators sign in to browser-based plant apps with the key, not a shared password. When the AI flags a defect, one touch on the key signs the verdict. Your quality team and auditors can see which key signed each verdict and confirm the record hasn't changed since it was signed.
No drivers and no USB storage: the key connects as a standard FIDO HID device. It isn't a keyboard and can't type.
The problem
Factory lines still run on shared passwords and unsigned logs
Enterprise zero-trust tools assume office laptops and one person per account. On a production line, neither holds.
Inspection records anyone can edit
Inspection cameras write their verdicts to plain files and databases. Anyone with access can change a reject (NG) to a pass (OK) afterward, and nothing in the log shows the change.
A YubiKey for every operator adds up
A YubiKey 5 NFC lists at $58 on Yubico's US store. Buying one for every operator on every shift is hard to justify.
YubiKey price as of October 2026.
How it works
One low-cost key for operator sign-in and signed verdicts
- PhysKeynRF52840 · FIDO2 / CTAP2USB HID
- EdgeJetson · Windows / Linux IPCSigned record
- Cloudflare TunnelOutbound onlyHTTPS
- Control planeauthentik · FastAPI · PostgreSQL
The edge agent sends signed records out through Cloudflare Tunnel. The site opens no inbound ports, and authentik, an open-source identity provider, checks every admin request before it reaches the control plane.
01
Off-the-shelf hardware, about $15 per key
PhysKey runs on the Nordic nRF52840 dongle, with firmware based on Google's open-source OpenSK. The bare board costs under $10 at Digi-Key; a case and provisioning bring it to about $15. Support for the Seeed XIAO nRF52840 is planned.
02
Enrollment in the browser, no drivers
During the pilot, admins enroll keys from Chrome or Edge and bind each one to an employee ID. The key shows up as a USB HID device, not storage, so USB-storage blocking policies leave it alone. Stations that sign verdicts run a small edge agent.
03
Hardware-signed inspection verdicts
When the AI flags a defect, the operator touches the key, and the key signs the timestamp, a hash of the image, and the decision. The private key stays on the dongle and is never sent to the PC or the server.
What gets signed
A verdict your auditor can trace to the key that signed it
Each record holds the time, the source camera, the decision, and a SHA-256 hash of the image. The image itself stays on site. The control plane checks the signature against the key's enrolled public key, uses the signature counter to reject replays, and links each record to the one before it by hash.
Edit a record and its signature no longer verifies. Delete one from the middle and the chain breaks. The chain alone can't show that the newest record was deleted or that the whole chain was rebuilt, so an auditor saves the current chain hash. Later checks against it expose any record deleted or rewritten up to that point.
- Signature verifies with the enrolled key
- Someone was present and touched the key (user presence)
- Signature counter advanced (blocks replays)
- Hash chain intact since the first record
Industrial compliance
How PhysKey maps to IEC 62443‑3‑3 system requirements
IEC 62443‑3‑3 applies to a whole system, and PhysKey is one part of it. PhysKey itself is not certified, including to the component standard IEC 62443‑4‑2. Here is what it covers today and what is on the roadmap.
| SR 1.1 | Human user identification and authentication | Each operator signs in to plant web apps through authentik with their own key, so accounts no longer need to be shared. |
|---|---|---|
| SR 1.2 | Software process and device identification and authentication | Roadmap: bind each key to a station. Today the edge agent names the source camera or PC inside the signed payload, so the name cannot change after signing, but the device itself is not authenticated. |
| SR 1.5 | Authenticator management | Admins enroll keys, bind each one to an employee ID, and revoke them in the control plane. |
| SR 2.8 | Auditable events | Flagged inspection verdicts become signed records. |
| SR 3.9 | Protection of audit information | Signatures expose edited records. Each key's hash chain exposes deleted ones, up to the last chain hash an auditor saved. |
Use cases
Where we are starting, and what comes next
Japan
Automotive and electronics inspection
Automakers and electronics OEMs ask their suppliers to prove inspection records weren't altered. Signed NG verdicts with image hashes give quality teams evidence they can hand to OEM auditors.
Thailand
High-turnover operator lines
Electronics and automotive plants in the Eastern Economic Corridor hire new operators all the time. At about $15, each person can have their own key instead of a shared password for plant web apps, and an admin can revoke a lost key in the control plane.
Global
Robots and AGVs (roadmap)
When a robot or AGV reaches a risky step, a person will approve it with a touch on the key, and the approval will become a signed record.
Threat model
What PhysKey protects against, and what it does not
A signature shows which key approved a verdict and that the record hasn't changed since. It doesn't show that the verdict was right. The nRF52840 has no secure element, and a published fault-injection attack (CVE-2020-27211) can read its flash with physical access to the board.
PhysKey assumes an attacker may take a key apart. If both the original and a clone keep signing, one of them eventually sends a counter that hasn't advanced, and the control plane rejects that record. A counter that fails to advance is a sign the key may have been cloned. The control plane also rejects every signature from a revoked key. Each key is bound to one employee ID, so a stolen key can sign only under that ID, and only until an admin revokes it. For sites that need a hardened chip, the same control plane accepts any FIDO2 key you allow.
Pilot program
Join the pilot
We are looking for plants in Japan and Thailand to run the first pilots with us. Tell us about your line and we'll reply by email.