From: tcmay@got.net (Timothy C. May)
Date: Tue, 29 Aug 95 13:13:01 PDT
To: cypherpunks@toad.com
Subject: Re: Florida Drivers Permits and a Hello
Message-ID: <ac68c16f1c021004dfea@[205.199.118.202]>
MIME-Version: 1.0
Content-Type: text/plain


This thread has more crypto relevance than some might think....

At 7:39 PM 8/29/95, Dave wrote:
>>What possible value could the LEAs get by having your thumbprint digitally
>>encoded on your driver's license?  It's not like the average cop-on-the-beat
>>is qualified to lift a fingerprint and compare it.  Even if he was, how
>>does it benefit that the fingerprint is on the license?
>>
>>This seems silly.
>
>There are device that will electronicly read fingerprints available now.  So
>with such a device, the LEO would know instantly if you were who you said
>that you were.

And it is possible with today's technology to do the following:

-- take a fingerprint

-- scan it, either linearly across some reference line (marked on the
license), or in a full 2D scan

-- have the issuing agency encrypt the resulting waveform (scan), using its
private key

-- print the resulting number on the license

Then, the validity of the license could be verified by:

-- the local checking agent (cop) takes the number printed on the license

-- runs it through the _public key_ of the issuing agency

-- gets back an analog waveform (scan)

-- can compare it directly to the actual fingerprint

This is the same scheme used by the once-extant company "Light Signatures"
as a means of foiling counterfeiters.

(A diagram makes all this much clearer...)

The scan can be done for digitized photos as easily as for fingerprints.
The point is simple: an analog signal of some sort can be "signed" by the
credential-issuing authority such that the signature can be easily checked
in the field, but not easily duplicated or forged.

Note that lottery tickets use a similar scheme. The winning number is
hashed or otherwise encrypted with a private key known only (so the theory
goes...) to the ticket-issuing agencies. This hash is also printed (at
least in some jurisdictions) on the ticket (usually in very small letters).
The winning number, which is announced and posted, cannot be used to print
up a "winning ticket" because the hash/encryption function is not known to
the counterfeiters.

A major player in this market, Scientific Games, has a printing facility
nearby my home.

I don't know if any driver's licenses have anything like this, but the
technology certainly exists, and should be coming pretty soon to all sorts
of documents.

--Tim May

---------:---------:---------:---------:---------:---------:---------:----
Timothy C. May              | Crypto Anarchy: encryption, digital money,
tcmay@got.net  408-728-0152 | anonymous networks, digital pseudonyms, zero
Corralitos, CA              | knowledge, reputations, information markets,
Higher Power: 2^756839      | black markets, collapse of governments.
"National borders are just speed bumps on the information superhighway."