This isn’t the case anymore: [Paul Stoffregen] has just released his Teensy Audio Library, a library for the ARM Cortex M4 found in the Teensy 3 that does WAV playback and recording, synthesis ...

he ended up building a U2F key with a Teensy LC, and in the process brought U2F to the unwashed masses. Universal 2nd Factor is exactly what it says on the tin: it doesn’t replace your password ...