I asked a similar question the other day: https://news.ycombinator.com/item?id=15431299 https://news.ycombinator.com/item?id=15431299 Basically, it all works

I asked a similar question the other day: https://news.ycombinator.com/item?id=15431299 https://news.ycombinator.com/item?id=15431299 Basically, it all works fine (I've verified it myself). I've been using a Yubikey for both SSH and challenge/response for quite a while now. A few days ago I started messing with U2F as well. The first that happens is gpg-agent "gets confused" after U2F auth and you have to remove/insert your key and/or re-enter your GPG PIN on next use (cf. linked thread). Next up for me is figuring out how to disable U2F on my Nano's and use separate U2F-only keys for that (without any conflicts or issues, hopefully). N.B.: I don't use the OTP functionality at all, currently. I'll probably try out the PIV stuff soon as well and I expect no conflicts or issues with the existing stuff (GPG, C/R, etc.) I have setup.