Apple Watch Auto Unlock Comes to Windows with Open-Source Tool
Windows users get a practical way to replicate Apple's hands-free lock/unlock experience, but the tool explicitly acknowledges its security is weaker than Auto Unlock: it only checks IRK and RSSI, so it cannot tell if the watch is on your wrist or if the signal is being replayed. It is best suited for trusted home or office environments, not as a high-security barrier.
Watch Unlock Windows is an open-source utility that gives Windows the same walk-away lock and approach-unlock behavior macOS has with Apple Watch. It tracks the watch's Bluetooth signal strength (RSSI): when you leave, the signal drops below a threshold and the PC locks; when you return and it crosses a higher threshold, it unlocks. The developer tests show about 0.17 seconds between returning and unlocking.
The watch is identified using the IRK from Windows' pairing data, because Bluetooth addresses rotate randomly. Unlock happens through a native Credential Provider that submits the saved account password to LogonUI. Setup involves four steps: pairing, binding with admin confirmation, entering the Windows account password (not PIN), and testing. Users can disable seamless unlock to require a keypress or mouse move, and can get a Bark push notification after each unlock.
Using RSSI as a presence signal is inherently fragile, but the tool is honest about it, which makes it a practical convenience for trusted environments rather than a security guarantee.
The architecture separates distance logic, the watch daemon, and the Credential Provider, so adding support for other wearable brands is straightforward via the DeviceAdapter.
Storing plaintext-recoverable credentials is unavoidable for any auto-login tool; DPAPI protects against other accounts and disk theft, but not against malware running as the current user.
The project forks an earlier incomplete version, showing that a small amount of Rust code plus a native Windows component can bring a polished macOS feature to Windows.