LUKS + Yubikey4 core error: no yubikey present


I’m using Kubuntu 21.10 (kernel 5.13.0-40-generic) with LUKS encrypted partitions that are unlocked by password + Yubikey4 ver 4.3.7.

Every so often I get yubikey core error: no yubikey present when trying to unlock the system.

When this happens it’s usually enough to just retype the password and then it proceeds normally.

Anyone have similar issues? Also I’ve noticed that sometimes Yubikey does not blink its LED when connected, which makes me think that this can have something to do with USB.

I’ve seen similar messages on the net, but they’re mostly about Yubikey not working at all because of wrong libraries and/or misconfiguration.


I’m not sure if i can be of much help, but I’m curious what instructions you used to configure that LUKS+Yubikey setup.

Hi! Essentially I used HMAC setup very similar to this

Also I tweaked swap setup so that it would allow hibernate to an encrypted partition.

P.S.: I have two LUKS slots: first is short password + Yubikey and the second is looong password in case I lose my Yubikey. This issue happens only on the first slot.