Recently I've written a few "random" articles dancing around the theme of randomness, why randomness is important, and how difficult it is to be truly random. I hope they convinced you that randomness in computing is important and hard to come by. It looks like someday very soon we will have a hardware component that generates quantum randomness. I hear that quantum is the best kind!
The takeaway from this series is that using software to generate random numbers is inherently problematic. Programs are all at some base level deterministic.
So it was with great delight that I just discovered a research group that was building working prototypes of very small (integrated circuit size) components that output random numbers based entirely on quantum principles.
Note: In recent history, there have been physical devices that could emit random numbers, but they were usually large (tabletop sized) and reasonably power-hungry systems. And most of them didn't generate random numbers at a high enough rate. Here's a typical unit.
The paper "Quantum entropy source on an InP photonic integrated circuit for random number generation," which appeared in the current issue of the journal Optica, describes a technique which is based on current research in photonic chips. In essence, the integrated circuit generates pulses of laser light at a low power threshold that is near the threshold for spontaneous emission. At that level, the phase of the laser pulse is (for reasons quantum) random. By doing optical interference with another laser pulse, it is possible to get a stream of bits that corresponds to the constructive or destructive interference of the two pulses. The result is a binary stream of the randomness of the first laser pulse. Here's a picture of the actual device resting on a coin:
A bonus from this invention, aside from its very low power, is that this quantum entropy-based chip can generate these random numbers at a rate of one gigabit per second. And, just to put some icing on the cake, the photonic technology is completely compatible with standard CMOS integrated circuit fabrication technology. Massive quantities of quality randomness will soon be an inexpensive commodity.
So, while this technology will be a boon for Monte Carlo simulations and cryptographers it will also find its way into the consumer's hands. Putting true random number generators in all of our smartphones will create an infrastructure for secure communications that is sure to make Edward Snowden smile.
It's quite likely that the NSA will not be smiling.