True (not pseudo) random number generators. What's out there?

Question

I am looking for affordable solutions that generate true random numbers.

I have found LavaRnd, which is a cryptographically sound random number generator. Does anybody has experience in this field and/or knows about other solutions?

PS: IMHO the SO question True random number generator did not really cover this

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EDIT:

My curiosity is more of academic nature. I don't want to know about PRNGs that are good enough for practical applications. I know they exist and that they will do.

Of course, generating true random numbers will require hardware devices. That's why I tagged this with hardware.

Answer 1

Your question depends on how you define "true random numbers". There are plenty of people out there who believe in a deterministic world and there is nothing random at all.

Answer 2

http://random.org/

Answer 3

True random numbers in computing does not exist and never will. Computers are deterministic, in that if you repeat the same experience under the same environment, the same result will be achieved.

What you get with computers are pseudo-random numbers, mostly depending on current circumstances: date, time, other variables like memory being used, network traffic at the moment, etc.

For example, some online poker sites, to guarantee to some extent the randomness of their dealt hands, had to install specific hardware that takes the ambient noise and generates random numbers based on that (not only that, but it's a major factor).

So, to have pseudo-random numbers that approximate to true randomness, you'll need to take outside factors into account.

Answer 4

You didn't specify an environment.

From the documentation for Linux's /dev/random

The random number generator gathers environmental noise from device drivers and other sources into an entropy pool. The generator also keeps an estimate of the number of bit of the noise in the entropy pool. From this entropy pool random numbers are created.

So this is a cryptographically secure random source, based on unpredictable input from such things as the arbitrary timings of ethernet packets, keyboard and mouse input, etc.

There's also Bruce Schneier's Yarrow PRNG server. Not truly random, but considered cryptographically secure.

... and also EGD, the Entropy Gathering Daemon. Written in Perl and hence portable across many platforms.

Answer 5

I've always been a fan of the Quantum Random Bit Generator: http://random.irb.hr/

Answer 6

There is an article in c't 2/2009 on true and pseudo random numbers. Other than LavaRnd also RandCam and VIA's PadLock are discussed.

Answer 7

"True random" generators are based on some form of physical white noise. The thing is, it's randomness is disputable. There are even projects to prove otherwise (although I'm rather skeptic about it)

Answer 8

For true random numbers, nothing beats particle physics and the good old Geiger Counter. You can get one with a USB interface for around $200.

Answer 9

As ramdom number generators go I have always liked the one made from lego....

Answer 10

I've always wanted to buy either the PCI or USB Quantum Random Number Generator, but I have no idea what they cost, and frankly it might be a lot! They do deliver a staggering 16 Mibit/s and 4 Mibit/s respectively of random numbers, though, usable on both *NIX boxes and Windows. That's more than I'd ever need!

Other than that, how 'bout a book full of 'em? A Million Random Digits with 100,000 Normal Deviates is perhaps the coolest book they sell on Amazon! I've yet to buy it, but it's only a matter of time. Must be very handy to have such a stock of true random numbers on your book shelve!

Answer 11

You could try a nice hot cup of tea.