Skip to content

OpenSK FIDO2 Authenticator


OpenSK released by Google is a fully open-source implementation for security keys written in Rust that supports both FIDO U2F and FIDO2 standards.

OpenSK is based on the FIDO2 specifications, which combine the World Wide Web Consortium’s (W3C) Web Authentication (WebAuthn) specification and FIDO Alliance’s corresponding Client-to-Authenticator Protocol (CTAP).

The nRF52840 MDK USB Dongle is supported by OpenSK. Taking advantage of the UF2 Bootloader, you can easily program the OpenSK firmware by just copying the .uf2-format image to the flash drive.

Get Involved

We think the best way to learn is by doing. The following sections take you through the basics of OpenSK and show you how to build your own OpenSK firmware.