That's true, but again - it requires hacking the online computer AND malicious device. I guess one could use some offline machine to copy over only the file wi

That's true, but again - it requires hacking the online computer AND malicious device. I guess one could use some offline machine to copy over only the file with the signed tx to be certain. :D > Every bit it can send out halves the security of your seed phrase. The device still needs to produce valid signatures in a reasonable time, so practically it can only leak handful of bits at the time.