Hi Carlos, Yes something like a digital signature that can be created/read automatically and not easily changed or found is exactly what I'm after. Mark -----Original Message----- From: thelist-admin at lists.evolt.org [mailto:thelist-admin at lists.evolt.org]On Behalf Of Carlos Costa Portela Sent: 04 October 2002 09:35 To: thelist at lists.evolt.org Subject: RE: [thelist] FW: MAC Addresses/Physical Address! On Wed, 2 Oct 2002, Mark Anderson wrote: > What I need to be able to show is a 'relatively' unique number that my > client can use in their database and can be interrogated programmatically > and returned to the database to check the system is up to date etc and the > number should not be easily altered by the client's users? Is valid a solution like a digital signature, for example?. Regards, Carlos.