[Cryptography] High volume thermal entropy from an iPhone

[Max Skibinsky]

> I actually think that from my points earlier point 4 is the most pertinent :
> in your case not only are you neither the designer nor the manufacturer but
> you also do not control the software updated that get delivered to you.

yes, #4 is certainly a thorny issue. I assume the "passive" attack
scenario here are hidden patterns in camera firmware and iOS that,
while appearing to us as "perfect" noise are in fact predictable from
low level software specifics (known to manufacturer but unknown to
us). Extreme case of active attack would be corrupt vendor that
actually produces far less noisy camera, and supplements it with
perfect noise generated from seed stamped into each camera firmware -
attack that is next to impossible to detect without reverse
engineering the silicon.

The only weak guarantee i see here is that comparing random
motherboard vendor, dedicated HSM vendor and Apple - the party i would
trust the most would be Apple for economic reasons. What is double
digit millions in reputation/brand damage to small vendors, is tens of
billions of damage to Apple - they have most motivations to keep all
parts of firm/soft ware stack secure. But of course thats just social
guarantee we are trying to avoid in first place.

 - Max