Seeding a random number generator in .Net

Question

I have a PRNG with nice properties which uses 6 UInt32s as state. I need to come up with a reasonable way to seed it. Two obvious possibilities are: 1) generate 6 random numbers using System.Random and use them as seeds; 2) generate 2 Guids with Guid.NewGuid(). Which would be better?

I do not need cryptographic security.

Answer 1

If it needs UInt32, then Random is more convenient? just Next(), Next(), Next() etc (and cast)... (use the same Random instance however - don't create new Random() each time).

It depends on what the intent is as to whether this offers enough randomness. Since this is just the seed, it should be OK...

Answer 2

Unfortunately System.Random() also requires a seed value. By default it uses the current Tick count which is predictable and not actually random. So you'll need a seed for Random which leads you back to your original question ...

I haven't ever used Guid.GetHashCode() as a seed before but my 2 second reaction is that doesn't sound like a bad idea.

Answer 3

Whether or not you need cryptographic security, why not just use System.Security.Cryptography.RNGCryptoServiceProvider to generate your random numbers? Unless there's a specific reason, like it's too slow, I can't see why you wouldn't use it. Since it is a cryptographic random generator, you'll get much better random numbers, and don't have to be worried about seeding it.