How are .NET 4 GUIDs generated?

Posted by mafutrct on Stack Overflow See other posts from Stack Overflow or by mafutrct
Published on 2010-05-03T12:19:43Z Indexed on 2010/05/03 12:38 UTC
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guid

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.NET

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.net-4.0

I am aware of the multitude of questions here as well as Raymond's excellent (as usual) post. However, since the algorithm to create GUIDs was changed apparently, I found it hard to get my hands on any up-to-date information. The MSDN seems to try and provide as few information as possible.

What is known about how GUIDs are generated in .NET 4? What was changed, and how does it affect the security ("randomness") and integrity ("uniqueness")?

One specific aspect I'm interested in: In v1, it seems to be about impossible to generate the same GUID on a single machine again since there was a timestamp and counter involved. In v4, this is no longer the case (I was told), so the chance to get the same GUID on a single machine ... increased?

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