[ale] [Fwd: Descramble That DVD in 7 Lines] on Linux

[Wandered Inn]

glen mccready wrote:
> 
> Forwarded-by: Nev Dull <nev at sleepycat.com>
> Forwarded-by: john at stoffel.org
> Forwarded-by: Jon Callas <jon at callas.org>
> 
> Descramble That DVD in 7 Lines
>         -- by Declan McCullagh
> 
> 9:00 a.m. Mar. 7, 2001 PST
> CAMBRIDGE, Mass. -- Descrambling DVDs just got even easier, thanks to a
> pair of MIT programmers.
> 
> Using only seven lines of Perl code, Keith Winstein and Marc Horowitz have
> created the shortest-yet method to remove the thin layer of encryption that
> is designed to prevent people -- including Linux users -- from watching
> DVDs without proper authorization.
> 
> Their "qrpff" program is a more compact cousin of the DeCSS utility that
> eight movie studios successfully sued to remove from the Web site of 2600
> Magazine. But unlike DeCSS, qrpff is abbreviated enough for critics of the
> Motion Picture Association of America to include in, for example, e-mail
> signature files -- and many already have.
> 
> "I think there's some value in demonstrating how simple these things really
> are and how preposterous it is to try to restrict their distribution," says
> Winstein, a 19-year-old MIT sophomore computer science major.
> 
> Winstein says it's folly for MPAA and its allies to try to restrict a
> 526-character program that can be handed out on business cards. "I'm
> showing the humor in trying to call these seven lines on a piece of paper a
> device," he says.
> 
> The probable spread of qrpff on business cards, on T-shirts, and bumper
> stickers closely resembles the distribution of encryption code in signature
> files and T-shirts a few years ago. Such civil disobedience flouted U.S.
> export laws in a kind of global keep-away game.
> 
> Programmer Adam Back managed to squeeze the RSA algorithm into just two
> lines of Perl.
> 
> Winstein and Horowitz, an MIT alumnus, are both members of the MIT Student
> Information Processing Board, the university's social group for programmers
> and like-minded folks. They jointly developed qrpff for a two-meeting
> seminar that Winstein taught earlier this year.
> 
> Unlike some other DVD-descramblers, qrpff doesn't include the necessary
> five-byte title key -- such as 153 2 8 105 225 -- which must be given to
> the program so it can perform the necessary decryption.
> 
> That, says Winstein, means qrpff doesn't violate the Digital Millennium
> Copyright Act, which the movie studios used in a federal lawsuit against
> 2600. "Even if whatever is enjoined by that injunction in New York is a
> violation of the law, I think there's a reasonable case to be made that my
> seven lines of Perl isn't," Winstein says.
> 
> The code takes advantage of a Perl command called eval, which evaluates the
> program text when it is executed:
> 
> $_='while(read+STDIN,$_,2048){$a=29;$b=73;$c=142;$t=255;@t=map{$_%16or$t^=$c^=(
> $m=(11,10,116,100,11,122,20,100)[$_/16%8])&110;$t^=(72, at z=(64,72,$a^=12*($_%16
> -2?0:$m&17)),$b^=$_%64?12:0, at z)[$_%8]}(16..271);if((@a=unx"C*",$_)[20]&48){$h
> =5;$_=unxb24,join"", at b=map{xB8,unxb8,chr($_^$a[--$h+84])}@ARGV;s/...$/1$&/;$
> d=unxV,xb25,$_;$e=256|(ord$b[4])<<9|ord$b[3];$d=$d8^($f=$t&($d12^$d4^
> $d^$d/8))<<17,$e=$e8^($t&($g=($q=$e14&7^$e)^$q*8^$q<<6))<<9,$_=$t[$_]^
> (($h=8)+=$f+(~$g&$t))for at a[128..$#a]}print+x"C*", at a}';s/x/pack+/g;eval
> 
> In a brief filed last month, the Bush administration sided with the movie
> industry against DeCSS, saying that software is not speech-protected by the
> First Amendment but can be regulated like parts to a machine: "This
> function is entirely nonexpressive, and thus does not warrant First
> Amendment protection."
> 
> U.S. District Judge Lewis Kaplan ruled last August that DeCSS was like a
> "common-source outbreak epidemic" that violated the law's prohibition
> against circumventing copyright-protection technology. The DMCA prohibits
> anyone from publishing or publicly distributing any hardware or software
> that "is primarily designed or produced for the purpose of circumventing
> protection afforded by a technological measure that effectively protects a
> right of a copyright owner."
> 
> 2600, with the help of the Electronic Frontier Foundation, has appealed its
> loss.
> 
> David Touretzky, a scientist in the computer science department at Carnegie
> Mellon University who testified for the defense, has included qrpff in his
> gallery of DVD descramblers. The gallery is designed to highlight the
> problem of dividing computer code into expressive and functional
> categories: It includes descramblers written in C, Scheme, English, and
> even haiku.
> 
> Last month, the MPAA demanded that Touretzky take down his page. He
> responded: "I would like to know if it is the intent of the MPAA to exert
> editorial control over scholarly publications by computer science faculty
> that deal with DeCSS, and if so, exactly which sort of publications will
> the MPA permit in the future, and which sort will result in legal threats
> such as your letter of yesterday."

--
Until later: Geoffrey		esoteric at denali.atlnet.com

"Great spirits have always found violent opposition from mediocre minds.
The
latter cannot understand it when a man does not thoughtlessly submit to
hereditary prejudices but honestly and courageously uses his
intelligence."
- Albert Einstein
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