I kind of doubt they would use some process like this for the iPhone, they probably program it in to avoid ID collisions. Yea I'm also curious if there is some name for this scheme where it generates some random pattern, I haven't heard of it myself and I previously worked in the semiconductor device world. Not saying it doesn't exist, just haven't heard of it. There are plenty of random sources that are used to generate a random bit such as thermal noise or clock jitter etc, but that is a single bit that you would then need a circuit to read that bit over and over to generate a random string like a UUID, and you would need some sort of statistics that would prove that that UUID that you generate over a finite time (probably a few milliseconds) is not highly self-correlated.