Yubikey 4
Today my new Yubikey arrived, a Yubikey 4. There’s a whole load of features packed into the YubiKey, but the only feature I really use is the OpenPGP applet which emulates an OpenPGP smartcard.
This is the only device that is trusted to see my private GnuPG keys at the points where I use them. It helps to keep track of where my keys are, as they can only be in a single place.