What LED colors mean
| Color |
Meaning |
| Green |
Idle |
| Blue |
Idle with button pressed |
| Orange |
Registration or Authenticate Request waiting for button to be pressed |
| Light Blue |
Registration or Authentication successful |
| Red |
Error or keys wiping request pending which needs 5 button presses |
Case for U2F Zero
I made a case that you can 3D print for a U2F Zero. See hardware/case.
Using the TRNG
You can access the U2F Zero's internal random number generator to get some high quality entropy.
# output
cd tools/u2f_zero_client
./client.py rng
# or seed
./client.py seed < /dev/urandom
Resetting the key
This is only valid for older 1.0 version builds. 1.1 version and up support unlimited keys.
U2F Zero 1.0 has 15 slots to register services. You can delete all registered keys by running the following
cd tools/u2f_zero_client
./client.py wipe
The LED will turn red and after pressing the button 5 times, all the keys will be wiped. You cannot undo this.