Re: [dvd-discuss] Comparing DeCSS with legitimate code.

[Jeremy Erwin <jerwin(at)ponymail.com>]

On Friday, May 24, 2002, at 12:40  AM, D. C. Sessions wrote:

> On Thu, 2002-05-23 at 20:11, Jeremy Erwin wrote:
>
>> Since plaintext transfer of VOBs to hard disk was not envisoned as a
>> legitimate operation by the inventors of CSS, DeCSS arguably 
>> circumvents.
>
> I rather suspect that the projection of images onto the walls
> of dance floors was not envisioned by the inventors of movie
> projectors, either.  So?
>
>
The argument was proposed that DeCSS, as a clone of CSS, does not 
circumvent-- as it performs the same actions. I argued that DeCSS was 
not, strictly, a clone-- hence, an argument could still be made that 
DeCSS circumvents, while CSS does not.

One could argue that libcss, insofar as it emulates (for compatibilty 
purposes) CSS does not circumvent, as, it, in it's normal mode of action 
does pretty much what CSS does-- decrypt bitstreams for playback.

The only differences lie in that one algorithm is authorized (in a very 
round about fashion) by the copyright holder-- the other is not. (I have 
no idea if a machine can be authorized-- I tend to think not...)

I made no claim as to the merits of anti-circumvention statutes.

As for designers not envisioning the eventual uses of their inventions, 
perhaps it would be useful to dredge up The Chicago Lock Company's Ace 
lock. The Ace lock, still common today, uses a tubular key, so as to 
present an unfamiliar target to would be lock pickers. It's not a 
particularly secure lock-- several companies sell (expensive) 
lockpicking tools for this lock.

(Please forgive the occasional error of fact)
It is most commonly found in bike locks, and computers (particularly 
servers). The bike lock companies use it because it still is harder to 
pick than a yale lock-- and presents an unfamiliar target for the would 
be thief. That is the original purpose of the lock-- envisioned by the 
inventor.

Computers use this particlar lock for an alltogether different reason-- 
a Ace lock requires less depth than a yale lock of comparable pin 
length. Enhanced security is a secondary consideration. The original 
;inventor probably did not concieve of this usage-- nevertheless, this 
usage does not contradict the original purpose of the lock. (and patents 
would have long since expired, etc)

Now, imagine if every Ace lock was stamped with a serial number. The 
Chicago lock company did a brisk business in selling replacement keys, 
and it had a secret algorithm associating a serial number with a 
particular key geometry. Of course, if one had access to this algorithm, 
the security of Ace locks would be diminished, but their monopoly would 
be broken.

Meanwhile, Congress passes a law barring the publication of such secret 
algorithms, classifying such material as circumvention devices. In the 
absence of such a law, the publication of such material need not be 
illegal-- but in the presence, even though there are rational, non 
burglary related arguments for publication...

Jeremy