It's always nice to see a new manufacturer in this field, but I have a few questions:
- Is the SE on Shell really 100% open-source?
- Can users disable the USB data transfer functionality without turning the device on?
- Any plans to accept Bitcoin or other cryptocurrencies as a payment method in your shop?
Our security model is quite different. It's modular: Shell is kept as simple as possible, while Keycard has the SE.
Even during signing, the keys don't leave Keycard - unlike with a Trezor Safe 3 for example. Check out the examples we put on our blog:
https://keycard.tech/blog/keycard-shell-radically-open-uniquely-secure , and especially the comparison table.
Keycard's SE is a standard JCOP4 by NXP - think credit cards, passports etc - with a proprietary part. Once there is a fitting, open source alternative, we would consider moving over.
USB data is turned off by default. If you like, you can keep that setting turned off, only ever use the usb port for charging, and use non-data cables only.
We are working on crypto payments. Mostly a legal thing. Sadly.