I don&#x27;t really see what&#x27;s new here, that made the author &quot;withdraw his endorsement&quot;. It&#x27;s an issue from 2014, about a device that has always been fully proprietary? Ok, so they make <i>other</i> devices that was in some small way open, and ran Free software. Great. But the yubikey devices have <i>never</i> AFAIK really been open in any meaningful sense. So, really this isn&#x27;t so much yubikey changing what they do, but rather the author not understanding what these devices were in the first place?<p>As far as I can tell, if you got one of these in the mail, there&#x27;d be no meaningful way you could verify that it hadn&#x27;t been tampered with anyway. So you&#x27;d just have to make a leap of faith, and assume it was &quot;secure&quot;? If you were prepared to do that, then fine use the yubikeys. If not, perhaps you should take a deeper look at your usb mouse and keyboard too. Did you verify that your keyboard isn&#x27;t running some code that might compromise your security?