So I might add proper ISO7816 smart card support to this thing now.

My reasoning is that if you were to lose your hardpass, the attacker won't be able to get hold of the (encrypted) private key. And since GnuPG Cards are supported by gpg (duh) and therefore pass, I don't have to implement my own crypto (which is basically the motto for this whole project).

There is a relatively old chip, the Philips/NXP TDA8029, that should be well suited to translate between the card's protocol and serial data. Someone has also written a driver for a reader based on that chip, and I hope I can adapt that one.

The SIM holder can easily obtained from AliExpress by searching for "samsung i9000 sim", and is originally from linkconn.

I managed to not use the backside of that PCB (which shouldn't really be an achievement to more professional designers), so I might fill that up with logos and text :D

The Smartcard I plan on using is the GNUPG card, and kernelconcepts.de sells one that has standard SIM size breakout tabs. (ordered already, but still in shipping **EDIT**: they came! man, a SIM card is huge compared to a Pi 0)

The board is already in the master branch of the github project.

**EDIT**: Now with primitive 3D model (FreeCAD). Yes, a standard SIM card is really that big compared to a Pi Zero.

Once I'll get my old boards from @oshpark and getting comfortable with smart cards in general, I'll continue working on this board.