How is the .net random generator implemented?

Question

I mean the standard (?) random generator in .net /c#

Random random = new Random(seed);
random.next();

I know there are tens or hundreds of methods in literature, but I cannot find out which one the .net framework uses currently?

Reason for asking question: if I draw a LOT of random variables, will I ever return to the same sequence. I know some RNG have this undesirable property.

Answer 1

Pseudo-random numbers are chosen with equal probability from a finite set of numbers. The chosen numbers are not completely random because a definite mathematical algorithm is used to select them, but they are sufficiently random for practical purposes. The current implementation of the Random class is based on a modified version of Donald E. Knuth's subtractive random number generator algorithm. For more information, see DE Knuth. "The Art of Computer Programming, volume 2: Seminumerical Algorithms". Addison-Wesley, Reading, MA, second edition, 1981.

http://msdn.microsoft.com/en-us/library/system.random.aspx

Answer 2

All calculations are based on seed. If you define a seed then for the same sequence of methods you will get the same results. If not then the default seed is the Environment.TickCount, therefore the same sequence of methods will generate different results on each run (not guaranteed in parallels).