My university uses client certs for some services. It&#x27;s a pain with tons of odd error cases. With a technical user base, this might actually have better worst-case experiences (but worse average-case, when client-side certs work and you always use one machine they are smooth).<p>It would be awesome if YubiKeys or other SmartCard-like devices were more widespread and better supported in browsers, because it would make client-cert workflows way easier. It&#x27;s really mostly an UX issue.