Re: Video & cryptography... (fwd)

Forwarded message:

> From: Adam Shostack <adam@homeport.org>
> Subject: Re: Video & cryptography...
> Date: Mon, 26 Jan 1998 13:56:57 -0500 (EST)

> Schneier, Wagner and Kelsey have done some work on an authenticating
> camera.
> 
> One issue to be concerned with is that what the camera sees is not
> always the truth.  Putting a film set together to film bigfoot is
> easy.  The fact that the film is authenticated as having come from the
> camera doesn't mean a whole lot in some cases.

Doesn't this same sort of issue arise from any other digital signature
process then? There should be nothing fundamentaly different between the
characteristics of a video camera signing a frame than a person signing
email.


    ____________________________________________________________________
   |                                                                    |
   |       The most powerful passion in life is not love or hate,       |
   |       but the desire to edit somebody elses words.                 |
   |                                                                    |
   |                                  Sign in Ed Barsis' office         |
   |                                                                    | 
   |            _____                             The Armadillo Group   |
   |         ,::////;::-.                           Austin, Tx. USA     |
   |        /:'///// ``::>/|/                     http://www.ssz.com/   |
   |      .',  ||||    `/( e\                                           |
   |  -====~~mm-'`-```-mm --'-                         Jim Choate       |
   |                                                 ravage@ssz.com     |
   |                                                  512-451-7087      |
   |____________________________________________________________________|

Jim Choate wrote:
| > From: Adam Shostack <adam@homeport.org>
| > Subject: Re: Video & cryptography...
| > Date: Mon, 26 Jan 1998 13:56:57 -0500 (EST)
| 
| > Schneier, Wagner and Kelsey have done some work on an authenticating
| > camera.

Dave points out that this was Schneier, Hall and Kelsey.

| > One issue to be concerned with is that what the camera sees is not
| > always the truth.  Putting a film set together to film bigfoot is
| > easy.  The fact that the film is authenticated as having come from the
| > camera doesn't mean a whole lot in some cases.
| 
| Doesn't this same sort of issue arise from any other digital signature
| process then? There should be nothing fundamentaly different between the
| characteristics of a video camera signing a frame than a person signing
| email.

	It arises in a different context; with a signature on paper,
you're generally indicating that you've read and consented to whats on
the paper, not that you created it.  The meaning of a camera signing a
video still is not obvious to me.  Is it intended to be 'this is what
we saw through the lens?' or 'this is what really happened?'

Adam


-- 
"It is seldom that liberty of any kind is lost all at once."
					               -Hume