<html>
<head>
<style>
.hmmessage P
{
margin:0px;
padding:0px
}
body.hmmessage
{
FONT-SIZE: 10pt;
FONT-FAMILY:Tahoma
}
</style>
</head>
<body class='hmmessage'>And the whole thread started with suggesting we allocate information bits to encode semantics. Which drastically heightens the risk of collisions, intentional or malicious.<BR><BR>
Just see guids as private to the trust domain, and we'll all fine. Grids should be publicly referred to by something riches, as an uri/url for example.<BR>
<BR>Best regards,<BR>Stefan Andersson<BR>Tribal Media AB<BR> <BR>Join the 3d web revolution : <A href="http://tribalnet.se/" target=_blank>http://tribalnet.se/</A><BR> <BR><BR><BR><BR>
<HR id=EC_stopSpelling>
<BR>
Date: Fri, 31 Oct 2008 20:10:41 -0700<BR>From: diva@metaverseink.com<BR>To: opensim-users@lists.berlios.de<BR>Subject: Re: [Opensim-users] [Opensim-dev] Grid Numberging<BR><BR>
<META content="Microsoft SafeHTML" name=Generator>Not to mention the dudes and dudettes who generate region UUIDs by hand... (a-hem)<BR>Purely random UUIDs that don't encode higher-order information are too fragile when there is a chance that people will get their hands on them. I'm not even talking about malicious manipulation, just simple human intervention.<BR><BR>Frisby, Adam wrote: <BR>
<BLOCKQUOTE cite=mid:63FAD4F222230A4EA79DE9E8BE6647352BE843@winxbeus19.exchange.xchg><PRE>Yeah, the reason I said 'almost' wasn’t because of a good UUID generator, - it's the bad ones.
IE, people using bad random sources, etc which dramatically increase the chance of a collision - ie if you are only getting 30 bits of randomness, you could run into a collision fairly quickly.
Adam
</PRE>
<BLOCKQUOTE><PRE>-----Original Message-----
From: <A class=EC_moz-txt-link-abbreviated href="mailto:opensim-users-bounces@lists.berlios.de">opensim-users-bounces@lists.berlios.de</A> [<A class=EC_moz-txt-link-freetext href="mailto:opensim-users">mailto:opensim-users</A>-
<A class=EC_moz-txt-link-abbreviated href="mailto:bounces@lists.berlios.de">bounces@lists.berlios.de</A>] On Behalf Of Sean Dague
Sent: Friday, 31 October 2008 4:48 PM
To: <A class=EC_moz-txt-link-abbreviated href="mailto:opensim-users@lists.berlios.de">opensim-users@lists.berlios.de</A>
Subject: Re: [Opensim-users] [Opensim-dev] Grid Numberging
Dr Scofield wrote:
</PRE>
<BLOCKQUOTE><PRE>Frisby, Adam wrote:
</PRE>
<BLOCKQUOTE><PRE>Shouldn’t UUIDs by definition be unique?
IE – if your generating them randomly a collision is almost
guaranteed to never ever occur.
</PRE></BLOCKQUOTE><PRE>"almost" being a key word here...
</PRE></BLOCKQUOTE><PRE>"...after generating 1 billion UUIDs every second for the next 100
years, the probability of creating just one duplicate would be about
50%. The probability of one duplicate would be about 50% if every
person on earth owns 600 million UUIDs.<A class=EC_moz-txt-link-rfc2396E href="http://en.wikipedia.org/wiki/UuidJusttokeep" target=_blank>"
http://en.wikipedia.org/wiki/Uuid
Just to keep "</A>almost" in perspective,
-Sean
--
Sean Dague / Neas Bade
<A class=EC_moz-txt-link-abbreviated href="mailto:sdague@gmail.com">sdague@gmail.com</A>
<A class=EC_moz-txt-link-freetext href="http://dague.net/" target=_blank>http://dague.net</A>
</PRE></BLOCKQUOTE><PRE>_______________________________________________
Opensim-users mailing list
<A class=EC_moz-txt-link-abbreviated href="mailto:Opensim-users@lists.berlios.de">Opensim-users@lists.berlios.de</A>
<A class=EC_moz-txt-link-freetext href="https://lists.berlios.de/mailman/listinfo/opensim-users" target=_blank>https://lists.berlios.de/mailman/listinfo/opensim-users</A>
</PRE></BLOCKQUOTE><BR></body>
</html>