Question

I know that you can bang away at GUID generation on single and multiple machines and it’s statistically unlikely to ever generate the same GUID twice.

There is lots of information on the internet proving this.

Can the same be said of 100s of Windows CE 4, 5 & 6 devices running applications based on the .NET Compact Framework 3.5 generating GUIDs?

I’m assuming yes but can’t find any information proving that the WinCE OS uses random numbers and that they are suitably random.

Can anybody provide such information and references?

Thanks,

J.

Answer 1

From an early article on Guid for the .NET Compact Framework

The .NET Compact Framework team constantly made tradeoffs between the
framework footprint size, performance, and implementation time. The
full .NET Framework Guid.NewGuid method calls the Windows API function
CoCreateGuid that calls UuidCreate to generate globally unique 128-bit
numbers. Unfortunately, these functions are not supported on the
Pocket PC, so the Guid.NewGuid method was not implemented for the .NET
Compact Framework.

This article proposes an algorithm which equals the windows version

It turns out that it’s easy to write a custom implementation of the
Guid.NewGuid method. The following shows a test application that
generates GUIDs on the Pocket PC. It uses a custom class called
PocketGuid, that uses the same algorithm as desktop GUIDs and is
discussed in more detail later in this paper.

Since 2.0 the actual compact framework contains the Guid.NewGuid method, I would think they included the mentioned code which results in the same strongness / uniqueness of Guids on WinCE.