You can associate multiple U2F keys with a Google account. Since the Yubico's U2F key is really cheap (I think ours were ~15 Euro a pop), it doesn't hurt to ass

You can associate multiple U2F keys with a Google account. Since the Yubico's U2F key is really cheap (I think ours were ~15 Euro a pop), it doesn't hurt to associate another key and put it in a safe somewhere.