Re: Thoughts on Message-ID generation

["David A. Cobb" <superbiskit@home.com>]

Stainless Steel Rat wrote:

> * "David A. Cobb" <superbiskit@home.com>  on Thu, 01 Mar 2001
> | Taking a clue from a different source, I believe the OMG - CORBA folk
> | have a scheme for generating unique ID's that folds your 60-bit NIC
> | number (which the mfgr's guarentee to be unique), the current UTC, and
> | maybe something else just for fun.
>
> Not so useful for non-Ethernet media.  Token Ring NICs use bewteen 32 and
> 48 bits for MAC addresses.  SLIP, PPP and PLIP have no MAC addresses to
> speak of, so this idea totally fails for them.  I don't know what fibre
> channel uses off-hand.  And there is the problem that modulo "something
> else just for fun" a multi-processor, single NIC machine is capable of
> generating two or more identical IDs.  Besides, there is functionally no
> difference between using system-name and the MAC address.
>
> | Now, a mail-message is clearly an <<object>>!
>
> ... you say that like it's a good thing.

I'm not sure!  It's about like saying every boson in the universe is an object.
So what!  How many bits do we need to count all of them?

>
>
> | So, given about a 128-bit number generated by such an algorithm and
> | encoding it Mod64 generates a string that isn't so long it's impossible
> | and enough numbers to last for a little while.
>
> And how do you propose to generate those 128-bit numbers and gurarantee
> their uniqueness, when you can't even guarantee that you can generate those
> numbers?

Once we agree on how do I uniquely identify ME, this reduces to my being
responsible for the uniqueness of the ID's of things (messages, resources, etc)
which I generate.  That's the basic "I name my own children" notion.  [Works for
most folk excepting George Forman.]  Now, if I start with my local approximation
of UTC - I think about 64 bits would count the milliseconds in the age of the
universe, I only need to add "something else just for fun" when I generate more
than one thing in a millisecond - not easy for me but my digital assistant under
my fingertips here can do many many provided they aren't too big or complex.

Hey, it's just more bits!  IPv6 addresses are 128-bits, maybe we add another
128-bits for the objects created at a given address.  I isn't totally
unmanagable.

>
>
> | For security purposes, one might want a number including your NIC#
>
> Assuming you have one.
>
> | run through some sort of one-way hash, but that might destroy the
> | uniqueness property.
>
> Except that good hash algorithms don't do that.
>
> | Some network guru, chime in here please with what damage - if any - a bad
> | guy could do if he knew my NIC#.  CORBA must have dealt with the same
> | security issues.
>
> Lessee... he could steal *all* of your network traffic if he is on the
> same physical segment.

Aha!  Yes, that could be a problem.
Did I get the CORBA scheme right?  This thing on my shoulders has lots of "senior
moments" these days.

>
> --
> Rat <ratinox@peorth.gweep.net>    \ Happy Fun Ball may stick to certain types
> Minion of Nathan - Nathan says Hi! \ of skin.
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--
David A. Cobb, The Superbiskit !
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