[mileswu]

> First of all I do not trust any hardware. It’s impossible to verify that the hardware doesn’t have a backdoor and randomness looks random even if tampered with.

Well if you can't trust any hardware, how can the author trust any off-the-shelf computer and CPU to generate the private key even if he is using Linux+GPG? For all he could know the CPU could contain a backdoor that performs the necessary arithmetic and operations incorrectly (in the process making the key weaker).

He is also trusting his CPU to do the session encryption correctly (even with his external smartcard). Perhaps the CPU could leak information about the session key to another processes, allowing people to decrypt your communications?

Now I trust my CPU and hardware, especially because we have little alternatives. Perhaps it would be better to use an external smartcard to generate the private key too, because the physical hardware is orders of magnitude less complicated than a CPU/computer, so you could verify the hardware contains no backdoors by examining the physical circuits using a microscope (I presume this would still be very hard to do but millions of times simpler than that for a modern CPU).

[acqq]

Smartcard is the whole computer, minus power supply and the clock. You are right that it's smaller than one x86 and the rest of your notebook or desktop though. Still you'd have to investigate all the hardware and software on your desktop that you use with the smartcard too -- how would you know that the desktop isn't just pretending to use your smartcard? And if you trust the desktop, why do you waste the time with the smartcard, as long as you make the whole setup only for you?