[meteorite-list] eBay bidder ID codes... decrypted

From: Nicholas Gessler <gessler_at_meteoritecentral.com>
Date: Thu, 06 Sep 2007 08:50:34 -0700
Message-ID: <7.0.1.0.2.20070906084123.06221420_at_ucla.edu>

A friend, Fred Brandes on the Cryptocollectors list, has figured out how
eBay constructs the new bidder ID codes for high priced items. It keeps
the robots away but anyone in the community can figure it out.
Here is his analysis with my notes in (parentheses):
Cheers,
Nick

===============================================

Bidder Bid Amount Bid Time
c***s( 449) US $821.52 Aug-30-07 09:26:13 PDT (this is codasaurus,
Fred Brandes)
c***a( 55) US $811.52 Aug-31-07 16:56:14 PDT (this is gmace888, George Mace)
c***a( 55) US $601.52 Aug-31-07 10:38:57 PDT (this is gmace888, George Mace)
c***a( 55) US $511.52 Aug-31-07 08:26:15 PDT (this is gmace888, George Mace)
h***p( 936) US $414.14 Aug-30-07 18:15:04 PDT (this is posthuman, Nick Gessler)
c***a( 55) US $400.00 Aug-30-07 07:11:02 PDT (this is gmace888, George Mace)

This is a change from the bidder1, bidder2, ... format eBay first
employed. eBay selects 2 characters from the userid at random but
also (and most importantly for our considerations) posts the actual
feedback rating of the bidder as well as the disguised userid.

This allows anyone who regularly watches listings for a somewhat
limited collectors genre (both in terms of items available and the
collecting "population") to match the disguised userid to the real
userid while verifying the match through the ratings.

I leave the identification of the 3 bidders in this listing to
anyone interested in cracking the "code".

An additional exercise would be to confirm whether the same userids
are jumbled in differing fashion across different listings. I
suspect that this would have to be the case since eBay would have to
account for two userids being altered to the same encoded userid.


p***h
Received on Thu 06 Sep 2007 11:50:34 AM PDT