Transaction GUIDs [Was: Writing a Sharp Zaurus PDA GnuCash Companion]

[Derek Atkins]

IMHO using /proc/sys/kernel/random/uid should be sufficient.  The
GUIDs are used to uniquely identify every object in the data file.
Every account, every transaction, every split has its own unique GUID.
A duplicate GUID would be very bad indeed.

-derek

"Colin Pinkney" <Colin.Pinkney@marconi.com> writes:

> Thanks for the reply.
> 
> So basically using /proc/sys/kernel/random/uuid should be ok then? AFAIK
> the GUID is only used for uniquely identifying a single transaction or
> other element, right? I didn't think it was used in any security stuff.
> 
> Colin
> 
> 
> 
> 
> linas@linas.org (Linas Vepstas)@lists.gnucash.org on 18/09/2002 07:12:42
> 
> Sent by:  gnucash-devel-admin@lists.gnucash.org
> 
> 
> To:   Colin Pinkney <Colin.Pinkney@marconi.com>
> cc:   gnucash-devel@lists.gnucash.org
> 
> Subject:  Re: Transaction GUIDs [Was: Writing a Sharp Zaurus PDA GnuCash
>       Companion]
> 
> 
> repsonding to very old email,
> now that I am getting email again...
> 
> 
> On Fri, Aug 23, 2002 at 12:38:40PM +0100, Colin Pinkney was heard to
> remark:
> >
> >
> > I was just looking at how GUIDs are generated, but couldn't quite figure
> it
> > out. Seems to  have something to do with randomly selecting md5sums of
> > files that constantly change.
> >
> > I'm know very little about pseudo-random algorithms and want to keep it
> > simple so I'm hoping /proc/sys/kernel/random/uuid has enough entropy. But
> I
> > guess in the end as long as it's a unique 128bit number (stored in hex
> > format) it doesn't really matter, does it?
> 
> it matters a lot. md5 has been mathematically proven to generate unique
> id's.  Most all naive algorithms fail to do so, in ways that seem subtle
> to the naive developer but are well knows to crypto types and hackers.
> 
> (the linux kernel uuid algo is probably quite good.)
> 
> --linas
> 
> 
> --
> pub  1024D/01045933 2001-02-01 Linas Vepstas (Labas!) <linas@linas.org>
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-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
       URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
       warlord@MIT.EDU                        PGP key available