I guess you can use https://github.com/FiloSottile/yubikey-agent https://github.com/FiloSottile/yubikey-agent to store an ssh key on a yubikey, and then use age

I guess you can use https://github.com/FiloSottile/yubikey-agent https://github.com/FiloSottile/yubikey-agent to store an ssh key on a yubikey, and then use age to encrypt to the ssh key. Getting minisign to sign using a key in a ubikey is not supported out of the box, but should be possible in the same way yubikey-agent works (after all, that's what it does when you authenticate an ssh session using a yubikey). You can ask Filippo Valsorda.