Excuse my ignorance but I don’t understand what a Smart Card is and how it interacts with Gpg4Win. By chance, the smart cards you mean are something like this one taken from Amazon here (Two-factor authentication key)
https://www.amazon.it/Thetis-Chiave-sicurezza- authenticator-Authentication/dp/B0821SK3PR/ref=sr_1_8?crid=1JI47G4MV3FCP&qid=1708018171&sprefix= key%202%20fatt,aps,214
Can you show me some examples to understand better?
Thank
Denis
Smart cards (and USB token keys like the one you linked) can be used to store your private key so you don’t have to save it on the computer(s) you are working with. This way you can increase your security because an attacker who has access to your computer cannot get your private key.
I don’t know trustworthy companies which are selling smart cards (because I didn’t do a research on this topic yet) but two companies are Nitrokey and Yubico.
In the wiki you can find out more about using Smartcards with Gpg4win.
Smartcards for CMS (e.g. for S/MIME or signing PDFs) can be ordered by a number of vendors. E.g. in Germany there is TCOS Smartcards - Overview » Telekom Trust Center (I did not test this particular card, this is just to give you an example)
There is also a special card for OpenPGP, see Search results for openpgp | FLOSS Shop EN
and OpenPGP card - Wikipedia for more pictures and links.