Do you mean the actual chip back and fourth? The inherent problem is that the 7816-d standard is a mess. It requires extremely small data exchanges on the order of seconds to get a cert out of the card.

This has been a mess since the mid 90s, when I first worked on these things.

Here a cruddy not at all usefule link to the standard:

http://www.cardwerk.com/smartcards/smartcard_standard_ISO781...