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New Method for Random Number Generation Developed
Science Daily is reporting that a German team has developed a new method of random number generation that they hope will improve security. "The German team has now developed a true random number generator that uses an extra layer of randomness by making a computer memory element, a flip-flop, twitch randomly between its two states 1 or 0. Immediately prior to the switch, the flip-flop is in a 'metastable state' where its behavior cannot be predicted. At the end of the metastable state, the contents of the memory are purely random. The researchers' experiments with an array of flip-flop units show that for small arrays the extra layer makes the random number almost twenty times more 'random' than conventional methods."
the generation of random number is too important to be left to chance.
Lets play a game, what XKCD am I thinking of?
Brilliant! Just assign a bit based on whether or not it works in a given Ubuntu release!
In Numerical Recipes for C they list several benchmarks for determining how good one random number generator is compared to another (based on various statistics measures) so it certainly is possible for one method to be more random than another. Read chapter 7 of that book for all the details you could possibly want on this subject (with references to even more information).
One way of generating a good random number in Linux is using /dev/random (which uses a hardware-based random signal as its source, I don't recall the details). However, it isn't fast enough for most applications, outputting only a few bytes per second of random information, although it can serve as a useful seed for other random number generators. Just run 'cat /dev/random > random_bytes.bin' to see its output.
I'm curious what rate random information can be generated using the method in the article. I'm presuming it's fast enough that an application could rely solely on this data without having to use it as a seed for a pseudo-random number generator. The question is how long does it take for the hardware to get to the state where its next value is unpredictable--in the case of /dev/random it's relatively long.
Question: why not simply use the random crap we all have on our PCs to generate random numbers? Say...choose 5 folders at random on a PC.
To understand recursion one must first understand recursion.
"Always forgive your enemies; nothing annoys them so much." - Oscar Wilde
Indeed. I listened to a podcast a while back in which Robert Krulwich (RadioLab?) discussed randomness with a researcher and how we think about randomness.
A scientist he interviewed stated that she assigned tasks to several different teams. For one team, she instructed them to flip a coin some fixed number of times (perhaps 100) and to then report the sequence of heads and tails (H H T H T T H T T T etc). For the second team, she instructed them to NOT flip a coin, but to simply write down a sequence that they think might be produced by the flipping of the coin. The teams each present their report, and she is not told which list was generated by which means.
However, she said it was easy to spot the "human" generated list, because it rarely contained a sequence of more than a few sequential entries of H H H H, for example. Whereas the truly random list might have even up to NINE sequential heads or tails. The average human just couldn't fathom such a "random" sequence [mathematicians excluded, naturally].
I only post comments when someone on the internet is wrong.
You're confusing Shannon entropy and true randomness. If you have a string of bits that are created by a process that is truly random but has a bias, it's easy to transform it into an unbiased (but shorter) string.
The problem with pseudo-random generators is that they're really not random at all: They're determinstic functions that map a seed onto a sequence of random bits. If you know the function and the seed, you can predict all of it, which leads to potential vulnerabilityies. The point of truly random numbers is that there's no possible information you could have that would enable you to predict it.
How is an infinite stream of 0s random?