YubiKey 4 and Ubuntu 15.10

yubi4

sudo apt-add-repository ppa:yubico/stable

sudo apt-get update

from: https://github.com/Yubico/yubioath-desktop

sudo apt-get install python-setuptools python-crypto python-pyscard python-pyside pyside-tools libykpers-1-1 pcscd -y

sudo apt-get install yubioath-desktop yubikey-personalization yubikey-personalization-gui -y

Insert YubiKey 4 (the ‘Y’ flashes green every ~4 seconds).

yubikey4start

yubikey4main

Now you’re set! https://www.yubico.com/support/documentation/

For easy Google 2FA (Thanks Yael): https://support.google.com/accounts/answer/6103534?hl=en