What I'm interested in is how you plan to protect the users' private keys (even from employees of your company)?
Nobody has access to the private keys, they are created by the chips inside Tangem Notes. You can't import or export these keys. You can't get them out in a lab, because the chip is an EAL6+ secure element. You can't hack the firmware it's based on EAL6+ cryptographic libraries, has minimal attack surface and 100% audited both internally and by one of the best independent security groups.
Thanks for explaining this. I think it is an important point to emphasize, so the users of your notes can feel protected.
And, good luck with your project. I hope it can help promote and popularize the usage of bitcoin, which can only be a good thing.