[Cryptography] Photojournalists & filmmakers want cameras to be encrypted

[Ray Dillinger]

On 12/15/2016 03:03 PM, Jan Dušátko wrote:
> 

> Current industry solution are use the metadata in picture format (i.e.
> EXIF). But for proper evidence, there are needs to got positioning,
> timestamp and camera ID, signed together in tamperproof hardware and/or
> use independent certification authority for timestamping of electronic
> signature.
> But there are no such things available.

Encryption, as such, is valuable but the value might be limited
by the reaction of people who do censorship.  It is hard to
imagine that the sort of people who confiscate cameras with
particular types of footage on them would not also confiscate
any camera specifically designed so that they couldn't tell what
kind of footage was on them.

If such a camera did exist, I think it would be confiscated at
*EVERY* checkpoint where anyone might seize an ordinary camera.
People protecting secrets will assume the worst (from their point
of view) every time such a device is found.

OTOH, a camera you can't see into probably wouldn't justify
the expense of jailing or torturing somebody - the response
would be limited to the seizure of the camera leaving the
journalists considerably safer.

Whether contents are encrypted or not, crypto hardware is very
much worthwhile to build into cameras, because such hardware
could also do crypto authentication for evidentiary purposes.
If the signing private key never leaves the camera, images and
video shot by it can be shown with a very high degree of
confidence not to be faked or altered.

A running signature scheme for video such that the signature on
every (hundredth or so) frame can be used to verify that none of
the preceding few thousand frames are missing or altered would
be pretty simple to design; it would just use a hash chain,
allowing detection of quick-cut edits and rearrangements that
might escape notice otherwise.

This is a serious issue in the age of digital editing.  If the
prosecution shows footage of the defendant kicking a puppy, the
defense can then claim it's faked and distribute footage of
every member of the jury doing likewise.

			Bear

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