For what it&#x27;s worth, most smartcard applets don&#x27;t typically store GPG objects but RSA keys (and also usually X.509 certificate objects that go along with them, as well as less-used RSA public key objects).<p>I use PIV (NIST SP 800-73) compliant smartcards with a PKCS#11 module I wrote (CACKey), it just works with &quot;ssh-add -s &#x2F;path&#x2F;to&#x2F;libcackey.so&quot;, then SSH away.<p>Additionally, there is a fork of OpenSSH called PKIXSSH that adds X.509 certificate support (in addition to the relatively recent, compared to the fork, support for OpenSSH certificates) and then I can authenticate to remote systems using my certificate -- which is helpful when my card is replaced, or if my certificate is revoked the CRLs can be used.