DVD-COPY_

How to copy a DVD, in three steps

Every method comes down to the same thing: read the disc, choose what shape the copy takes, then keep it or burn it.

Home-made discs copy with no extra steps. Commercial movie discs are scrambled with CSS, which changes both the tools you need and the law that applies. The full guide covers each method on Windows, macOS and Linux.

Open the step-by-step guide

The case: Universal City Studios v. Reimerdes

In October 1999 a small Windows program called DeCSS appeared on a mailing list for developers trying to get DVD playback working on Linux. It could read a movie off a scrambled DVD without a licensed player.

Copies spread to hundreds of websites within weeks. This was one of them. In January 2000, eight movie studios sued three people in federal court in Manhattan under the Digital Millennium Copyright Act, which was barely a year old: Eric Corley, publisher of 2600: The Hacker Quarterly; Roman Kazan; and Shawn Reimerdes, who had posted DeCSS on dvd-copy.com. The case took the name of the first defendant listed.

It became the first major test of the DMCA's ban on distributing tools that get around copy protection, and of whether publishing source code is protected speech.

1. 1996

   DVD launches with CSS

   The Content Scramble System, a 40-bit cipher, ships on the first DVD-Video discs. Only licensed players are given keys.

2. May 1999

   dvd-copy.com is registered

   The domain is registered a few months before the code that would make it part of a lawsuit.

3. Oct 1999

   DeCSS is released

   The program is posted to the LiViD mailing list. Its source code leaks later the same month and is mirrored around the world.

4. Jan 2000

   The studios sue

   Universal, Paramount, MGM, Tristar, Columbia, Time Warner, Disney and Twentieth Century Fox file in the Southern District of New York. Judge Lewis A. Kaplan grants a preliminary injunction against posting DeCSS.

5. 2000

   Two defendants settle

   Reimerdes and Kazan enter consent decrees with the studios. Corley and 2600 continue to trial.

6. Aug 2000

   The studios win at trial

   Kaplan rules that posting DeCSS, and knowingly linking to it, violates the DMCA (111 F. Supp. 2d 294).

7. Nov 2001

   The appeal fails

   The Second Circuit affirms under the name Universal City Studios v. Corley (273 F.3d 429). The defendants do not take it to the Supreme Court.

8. Jan 2003

   Jon Lech Johansen is acquitted

   The Norwegian teenager prosecuted for his part in DeCSS is cleared by an Oslo court, and again on appeal that December.

What a few hundred lines looked like

This site does not host DeCSS or link to copies of it, and the reason is specific to this domain: the operator settled the case by consent decree and agreed not to post the program or link to it. The listing below is a simplified sketch of the general shape of a descrambler, for readers who have never seen what the argument was about. The keys are placeholders, the cipher is a toy, and it will not decrypt a DVD. For how the real cipher worked, step by step, see the encryption explainer.

/*
 * css_sketch.c - ILLUSTRATION ONLY
 *
 * The rough shape of a CSS descrambler. This is not DeCSS: the keys
 * are placeholders, the cipher is a toy, and it decrypts nothing.
 */

#include <stdio.h>

/* A CSS key is 40 bits: five bytes. */
typedef struct { unsigned char key[5]; } css_key_t;

/* Licensed players each carry a player key (placeholder shown). */
static css_key_t player_key = {{0x00, 0x00, 0x00, 0x00, 0x00}};

/* Each title on a disc has its own key, unlocked by the disc key. */
static unsigned char title_key[5];

/*
 * A DVD sector is 2048 (0x800) bytes. A real descrambler runs two
 * shift registers to make a keystream; this loop only gestures at it.
 */
void descramble_sector(unsigned char *sector) {
    int i;
    for (i = 0x80; i < 0x800; i++) {
        unsigned char k = title_key[i % 5];   /* toy keystream */
        sector[i] ^= k;
    }
}

/*
 * "Computer code is not purely expressive any more than the
 *  assassination of a political figure is purely a political
 *  statement."  - Judge Lewis A. Kaplan, 2000
 *
 * A lot of programmers disagreed, and said so in code.
 */

How 472 lines became an argument

The real program was small, a few hundred lines of C. What made it matter was not its length but the claim the studios built on it: that distributing it, or even linking to it, was illegal under a year-old law, whatever you did with it afterward. The court agreed. The question underneath, whether banning a piece of code is the same as banning speech, is why the case is still taught.

Programmers answered the ruling by making the point impossible to miss. They could not all be enjoined, so they turned the code into forms a court would have to call expression:

• It was printed on T-shirts and ties, worn into the courtroom, with the descrambling routine on the front.
• It was rewritten as a haiku hundreds of stanzas long, and set to music as a song with the steps as lyrics.
• It was encoded as a very large prime number, so that merely naming the right prime was, in effect, naming the program.
• It was mirrored to hundreds of sites in days, the Streisand effect before the phrase existed, which is the practical reason revoking a leaked key changes nothing.

None of this put the code back on this site, and it is not here now. The lasting content is the explanation of how the cipher worked and why the case went the way it did, which you can read without anyone needing to ship a circumvention tool.