What is the most secure seed for random number generation?

Question

What are the most secure sources of entropy to seed a random number generator? This question is language and platform independent and applies to any machine on a network.

Answer 1

THIS IS A GUESS! Crypto geeks please correct if I've got it wrong

The official algorithm for UUID/GUID at this point returns a result that is run through a cryptographic hash function - it takes known information, such as time, mac addr, and a counter to form a UUID/GUID and then runs this through a cryptographic hash to ensure that the mac address cannot be extracted.

I believe you can XOR this down to the number of bits you require for a seed with a reasonably good guarantee that the resultant value is equally distributed over the number space defined by your desired bit count. Note I am not claiming this is secure, only that this action should produce a value that distributes evenly across the bit space over time.

Answer 2

Random.org offers a true random number generator web service, "seeded" by the atmospheric noise.

You get 200,000 random bits for free each day, up to the 1 million random bits cap after that you should top up your account, it gets as cheap as 4 million bits per dollar.

Answer 3

First you need to define the actual use/purpose of the random number generator and why do you think in has to pass so high security standard? The reason I ask is that you mentioned picking it from the could - if you are using it indeed for security purposes then securing the source and the channel to send it around is much more important than anyone's academic knit-picking.

Second element is the size of the actual random numbers you need - big seed is good but only if the number generated is also big - otherwise you'll just be reading the small part of the generated number and that will increase your risk.

Look into reconfigurable ciphers, rather than things like SHA or AES. Here are 2 research papers if you want to read and verify how and why they work:

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.97.6594&rep=rep1&type=pdf http://www.springerlink.com/index/q29t6v1p45515186.pdf

Or grab any reconfigurable GOST cipher source code you find on the net and then you an either feed it just any basic seed (like concatenated "ticker" plus a web server node ID (if it's in a web farm) plus a part of response on any internet news site that changes top news all the time or you can feed it highly controlled initial seed (which you can make on your own) and use a light pseudo-random sequence for selecting further cipher configurations. Even NSA can't break that one :-) Since it's always a different cipher. For actual crypto purposes one virtually has to use very controlled initial seed just to be able to replicate the sequence for validation. That's where we go back to first item - securing the source and distribution.

Answer 4

The most secure seed is a truly random one, which you can approximate in practical computing systems of today by using, listed in decreasing degrees of confidence:

• Special hardware
• Facilities provided by your operating system that try to capture chaotic events like disk reads and mouse movements (/dev/random). Another option on this "capture unpredictable events" line is to use an independent process or machine that captures what happens to it as an entropy pool, instead of the OS provided 'secure' random number generator, for an example, see EntropyPool
• Using a bad seed (ie, time) and combine it with other data only known to you (for instance, hashing the time with a secret and some other criteria such as PIDs or internal state of the application/OS, so it doesn't necessarily increase and decrease according to time)

Answer 5

(((PI X current thread ID) X current process ID) / tick count) x pi

Answer 6

Simple solution if no additional random hardware are available.

Use milliseconds, mouseX and mouseY to generate a seed.