Big difference, you're only trusting the host computer (and the JTAG dongle) once. This is manageable, use an airgapped junk laptop with no HDD or similar if yo

Big difference, you're only trusting the host computer (and the JTAG dongle) once. This is manageable, use an airgapped junk laptop with no HDD or similar if you're ultra paranoid. Sure perhaps the firmware is compromised and leaking data through some super exotic attack but I mean come on. That should give you a pretty reasonable level of confidence. You can never 100% trust a device you didn't design and fabricate every aspect of yourself, there's always some risk with any hardware token. I'd also argue that trusting your host computer is certainly better than trusting the supplier. Shifting the burden of trust from a device you don't control to one you do is at least an improvement.