Re: UUID's

On Tue, Jun 21, 2011 at 3:39 AM, Nathan Kitchen <> wrote:
> Hi.
> I'm not sure if this is the place to raise this, it's basically a request
> for consideration of an API which I don't believe exists and would probably
> be most useful within web apps: a UUID generator.
> Earlier this week I hit a real-world issue where I needed to generate a UUID
> from JavaScript. It's possible to do this using Math.random, but these
> aren't guaranteed unique in the same way as version 1 UUID's (generated via
> a time-based algorithm). Decent write-up here (not mine):

I doubt exposing MAC addresses would be considered for a web API, for
privacy reasons.

The probability of a collision with random (version 4) UUIDs is small
enough to be acceptable for the overwhelming majority of uses.  You do
need a cryptographic-quality random number source for that, which
there's been work on recently.  You definitely don't want to use
Math.random for this.

Glenn Maynard

Received on Tuesday, 21 June 2011 08:04:34 UTC