Quote from: CAFxX on June 21, 2011, 04:33:28 PM

Hmm, no. ATmega8 runs at 16MHz while the ATmega328 can run at 20MHz, so it's roughly 25% faster.

Ah, I'd forgotten about that - most of the designs out there are at least vaguely Arduino-based and so run at the slower 16MHz speed.

Quote from: CAFxX on June 21, 2011, 04:33:28 PM

IIUC the project I linked above is using a capacitor connected to one of the ADC as a source of randomness. It might not be as good as one of those TRNGs, but with some decent entropy estimation, followed by equalization and whitening it should make a decent entropy source.

Hopefully, yeah. I was vaguely looking at a chip with an integrated RNG for a similar project, but it's way overkill and a bit too expensive and hard to work with. (Plus, I dropped the project after discovering there were bigger security issues related to Bitcoin *cough*exchanges*cough*.)

Quote from: CAFxX on June 21, 2011, 04:40:11 PM

Just a quick note... the one above wouldn't be really secure as is, because a secure design would at least require a display and confirmation button (to be secure against arbitrary software running on the host and - to a limited extent - against theft of the key).

Which is a pain, yeah. There are various potential options out there such as clones of Nokia LCDs though.