People carry credit cards that need nothing but a signature -- a real written autograph -- for small payments, I think the barrier to entry in terms of security

People carry credit cards that need nothing but a signature -- a real written autograph -- for small payments, I think the barrier to entry in terms of security is pretty low, and the comparison between app and SD storage or app and HW storage with the ability to control the platform is a notable difference, if small though in comparison to a sheer unlimited amount of risk. PS: So what, it can be in the same embedded system, it doesn't need to be bridged. The separate antennas might still communicate, though.