Maybe the Tomu discussed in another comment here would be a good starting point. We're really focused on the Kickstarter now, so unlikely we'll have time to do it ourselves in the next, say, month or two. But the code is open now :)

I personally use a Nano, but only for limited use cases like VPN. I don't like it for web access to Google/Facebook/Github simply because it feels like someone else could get access to it easily. Of course it's more like a feeling than a real threat.

It'd be interesting to see some numbers on sales, to see if it's worth from a business perspective.

Edit: grammar

We'd love to make something small like the Yubikey Nano!

Right now it'd be a bit tough, because to fit our chipset [1] in that tight space, it would likely involve making a custom IC package [2] or placing silicon die's directly on the circuit. I think it'd be really cool to do that, and if we get enough sales/interesting, we'll definitely go that route.

Using something like the Tomu seems promising as well. It doesn't have the same security features and is just an M0 core, so it's not the best fit.

[1] https://i.imgur.com/sVQ34em.pnghttps://i.imgur.com/sVQ34em.p...

[2] http://www.icproto.com/

If you get an ECAD/EDA tool you could do some work to reduce the size of the board.

From what it looks like, you can squish things together by a lot still and replacing components could further reduce it.

Though it's unlikely you'll be able to match the Yubi Nano easily unless you go for some expensive decisions (expensive unless you get a couple thousand keys).

I think if we had a single chip solution, we could make it work, but since we're using 2 chips, it would be tight. I posted schematic in other comments.

Maybe one "affordable" idea could be to stack 2 two-layer PCBs XD.