How deterministic Are .Net GUIDs?

Question

Yesterday I asked Are GUIDs generated on Windows 2003 safe to use as session IDs? and the answer combined with combined with this article GUIDs are globally unique, but substrin

Answer 1

It is almost impossible to get a duplicate guid considering the possiblities of getting one. Here are some quick math facts

Grains of sand in the world 75,000,000,000,000,000,000

Number of GUIDs 340,282,366,920,938,463,463,374,607,431,770,000,000