I could imagine hardware built to grab public keys, and I could imagine such in a general purpose computer. However in the end there are a large number of prob

I could imagine hardware built to grab public keys, and I could imagine such in a general purpose computer. However in the end there are a large number of problems so this is not a scenario to worry about. Yea, just generate the key and be done with it. But the problems include: 1. So suppose you build into a computer an effort to recognize some public key generation routines and intercept the key from memory. This could be done, but updating the firmware code (since it is hidden from the user of the computer) is pretty hard so it only works on versions current at the time of manufacture. If you have had the computer for a few years, such recognition would seem iffy. Additionally this gets more complex when supporting more implementations.... 2. Ok, so the computer malhardware has got the key, so what can it do with it? If you send the key over the internet, someone at some point may detect it. Likely the best scenario would be to store it and wait for some attempted handshake on, say, a firewire port, and then send it out then. Or one could wait for an SSH connection to an NSA-used cert for something like Google, but certs expire so that attack won't be worth it. Tinfoil mode is interesting but part of the benefits are thinking through the possible exposure of something like a compromised piece of hardware. Again, suppose the RNG is compromised. usually this means one can guess future values based on past values. An attack without past values is worthless, so it is unlikely to be helpful with regard to public key encryption as you point out.