Security for individual items

From: Mike Maz (mike_at_sinfonia.net)
Date: 12/29/03 

Date: 29 Dec 2003 11:49:41 -0800

I have a question regarding the registration of items. This isn't
really directly a security question, but it crosses over.

I have a bunch of $20 items that are sold through a website and bought
and sold everyday. Once they are delivered I need a foolproof way to
know who is in posession of the item if it is sold.

For example, person "A" buys and item and it is shipped to them.
Person "B" purchases the item from person "A" and needs to register it
on our website so that we can track the item for them. But we need to
have person "A" NOT be able to re-register the item once it has been
registered by person "B" unless it is again in their physical
posession at a later point.

I've thought about key fobs and RSA SecurID tags for the items, but
they seem a bit expesive for $20 items.

Is there some other way to handle this type of registration system
where only the person in posession of an item is able to register it?
Any help would be appreicated!

Miguel