anti-copy

How would it be possible to create files that KNOW they are 
a copy?  I don't mean ones that look at the mod date, but a 
system that is near fool-proof.
	Just something I've pondered...

		Daark

Did someone just publish the list address in a newspaper again ?  It seems
to be one of those days....

Daark writes:
> How would it be possible to create files that KNOW they are 
> a copy?  

It's not, to the great dismay of the Software Publishers Association (or 
whatever they're called).

-Futplex <futplex@pseudonym.com>

futplex@pseudonym.com said:
>> Daark writes: How would it be possible to create files that KNOW they 
>> are  a copy?  

> It's not, to the great dismay of the Software Publishers Association 
> (or  whatever they're called). 

Not to pick nits, but I was deeply into cracking^h^h^hbacking up 
software in the 80's, when I got my first Apple II complete with
4K of RAM.

There are several schemes of copy protection that were used, like strange
sector/track interleaving, and burning the floppies with lasers to
render certain sectors unreadable/writable.  The program would attempt
to read that area of the disk, and if it couldn't it was on the original
media.  

Of course, this was in the days before 20MB MFM drives became the rage,
when Woz was king.

I guess the only way for a program to know if it was a copy
would be to have itself figure out what track/sector it is on and inject
and/or compare that information into the executable.  But since this 
information is no longer easy to come by as operating systems become 
more protected, this wouldn't be viable.  Especially if you take into
account that disks go bad, and backups are needed.

More importantly, it would be very easy to hunt down and replace with 
NOPs.  More so than taking out the dreaded, "enter the phrase on line
3 on page 25 on your manual..."

To summarize, its possible (under _some_ operating systems), but it is 
not a good solution to the problem.

-----BEGIN PGP SIGNED MESSAGE-----

Hello cypherpunks@toad.com (Cypherpunks Mailing List)
  and turner@TeleCheck.com
 
turner wrote: 
> futplex@pseudonym.com said:
> >> Daark writes: How would it be possible to create files that KNOW they 
> >> are  a copy?  
...
> would be to have itself figure out what track/sector it is on and inject
...
Defraggers, anyone?
...
> To summarize, its possible (under _some_ operating systems), but it is 
> not a good solution to the problem.

How about if you control the operating system and everything, is
it then possible to demonstrate that you don't have other copies?
(Ie escrow agent is able to prove to customer that info destroyed.)

Presumably this would be based on QM, EPR 'paradox' or something like that.
I've read about something called "Quantum Eraser", but I don't know
whether that could be used to store useful info (the vague description
was from an "isn't time weird" viewpoint and erased boring stuff).

Anybody better in QM?

However, I don't think that you'll be able to provide "only one copy",
because once that copy is received and read once the recipient can
recreate it.


Hope I'm making sense...

Jiri
- --
If you want an answer, please mail to <jirib@cs.monash.edu.au>.
On sweeney, I may delete without reading!
PGP 463A14D5 (but it's at home so it'll take a day or two)
PGP EF0607F9 (but it's at uni so don't rely on it too much)

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