From: chen@intuit.com (Mark Chen)
Date: Tue, 7 Feb 95 16:58:57 PST
To: tcmay@netcom.com (Timothy C. May)
Subject: Re: Seals and Sealing Waxes
In-Reply-To: <ab5d0f8b040210047448@DialupEudora>
Message-ID: <9502080056.AA14295@doom.intuit.com>
MIME-Version: 1.0
Content-Type: text/plain



> "All crypto is economics," and this is what made seals and sealing wax so
> useful for so long. Saying "seals were duplicatable from the start" does
> not mean this feat was easy, even if technically possible.
> 
> In fact, the fine details produced by a good seal are hard to exactly
> emulate with a copy. Even on a two-dimensional surface. And with the advent
> of three-dimensional surfaces, which sealing wax made possible, the fine
> detail of a good seal was in fact very hard to forge.
> 
> Not impossible, but very costly with the technology of the day. Or even the
> technology of _today_. After all, paper currency is largely based on seal
> technology, with various embossing, printing, etc. methods used (on special
> paper) that remain fairly hard to duplicate.

The House Banking, Finance and Urban Affairs Committee last year held
hearings on the redesign of the U.S. currency.  Some of the testimony
about physical document security was pretty interesting (for those
with the requisite proclivities).  I only have a hardcopy, though if
enough people are interested, I might be persuaded to scan some of it
in.


--
Mark Chen 
chen@intuit.com
415/329-6913
finger for PGP public key
D4 99 54 2A 98 B1 48 0C  CF 95 A5 B0 6E E0 1E 1D