Re: Copyright enforcement through crypto

[Phil Karn <karn@qualcomm.com>]

>I'd like to explore the technical problems of enforcing copyright 
>restrictions through encryption and custom viewing software.

This job is pretty much unsolvable in the long run, because you have
to give all your secrets (algorithms and keys) to your "enemy". You
can slow him down a bit, but eventually he'll reverse engineer the
system -- especially if it runs on general purpose computer hardware.
It may be difficult, but it only needs to be done once because the
results can be quickly and widely disseminated in the underground.
Even without breaking the system per se, legitimate users will figure
out ways to copy its decrypted output and give it to their friends.

>Obviously, the goal would be to get really good copyright material on
>the net, like first run movies, when we have the bandwidth.

Why is this necessary? Many cable TV systems already carry
considerable amounts of copyright material despite having very weak
scrambling systems.  Even a strong system such as Videocipher II+,
which is based on the physical security of custom hardware, can still
have its output recorded and duplicated. Many cable companies openly
welcome VCR users -- they know it increases the appeal of the service.

What the photocopy machine started and the VCR moved into high gear,
the computer and the network will probably finish.  As John Perry
Barlow puts it, "Copyright is dead". It's not a matter of whether
copyright is morally right or wrong. It is simply going to become
utterly unenforceable -- like it or not. Instead of trying to patch it
we should find workable alternatives to replace its role in
compensating authors for their efforts.

Phil