DeCSS is a computer program capable of decrypting content on a DVD video disc encrypted using the Content-Scrambling System (CSS). A computer program is a collection of instructions that describe a task, or set of tasks, to be carried out by a computer. ... DVD (Digital Versatile Disc or Digital Video Disc) is an optical disc storage media format that can be used for data storage, including movies with high video and sound quality. ... “Cipher” redirects here. ... Content Scramble System (CSS) is an encryption system used on some DVDs. ...

Origins and history

A fragment of the DeCSS code, which can be used by a computer to circumvent a DVD's copy prevention.

DeCSS was devised by three people, two of whom remain anonymous. It was released on the Internet mailing list LiViD in October 1999. The one known author of the trio is Norwegian programmer Jon Lech Johansen, whose home was raided in 2000 by Norwegian police. Still a teenager at the time, he was put on trial in a Norwegian court and faced a possible jail sentence of two years and large fines, but was acquitted of all charges in early 2003. However, on March 5, 2003, a Norwegian appeals court ruled that Johansen would have to be retried on charges that he violated Norwegian Criminal Code section 145. The court said that arguments filed by the prosecutor and additional evidence merited another trial. On December 22, 2003, the appeals court agreed with the acquittal, and on January 5, 2004 Norway's Økokrim (Economic Crime Unit) decided not to pursue the case further. DeCSS algorithm in C. I created this image. ... DeCSS algorithm in C. I created this image. ... Copy prevention, also known as copy protection, is any technical measure designed to prevent duplication of information. ... Livid was an Australian alternative rock music festival, which was held annually from 1989 to 2003. ... Jon Johansen (DVD Jon) Jon Lech Johansen (born November 18, 1983 in Harstad, Norway), also known as DVD Jon, is a Norwegian (his father is Norwegian and mother is Polish) who is famous for his work on reverse engineering data formats. ... This article is about the day. ... 2003 (MMIII) was a common year starting on Wednesday of the Gregorian calendar. ... December 22 is the 356th day of the year (357th in leap years) in the Gregorian calendar. ... 2003 (MMIII) was a common year starting on Wednesday of the Gregorian calendar. ... January 5 is the 5th day of the year in the Gregorian calendar. ... shelby was here 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... Økokrim (full translated name: Norwegian National Authority for the Investigation and Prosecution of Economic and Environmental Crime; Økokrim is short for Økonomisk Kriminalitet (Economic Crime)) is Norways central unit for fighting economic, environmental and computer related crimes. ...

The program was first released on October 6, 1999 when Johansen posted an announcement of DeCSS 1.1b, a closed source Windows-only application for DVD ripping, on the livid-dev mailing list. The source code was leaked before the end of the month. The first release of DeCSS was preceded by a few weeks by a program called DoD DVD Speed Ripper^[1] from a group called Drink or Die, which didn't include source code and which apparently did not work with all DVDs. Drink or Die reportedly disassembled the object code of the Xing DVD player to obtain a player key. The group that wrote DeCSS, including Johansen, came to call themselves Masters of Reverse Engineering and may have obtained information from Drink or Die.^[2] October 6 is the 279th day of the year (280th in leap years). ... Year 1999 (MCMXCIX) was a common year starting on Friday (link will display full 1999 Gregorian calendar). ... Microsoft Windows is the name of several families of proprietary software operating systems by Microsoft. ... Source code (commonly just source or code) is any series of statements written in some human-readable computer programming language. ... DrinkOrDie (DoD) was an underground software cracking and warez trading network during the 1990s, shut down by a major raid in 2001. ... In computer science, object file or object code is an intermediate representation of code generated by a compiler after it processes a source code file. ... This article or section contains information that has not been verified and thus might not be reliable. ...

The CSS decryption source code used in DeCSS was mailed to Derek Fawcus before DeCSS was released. When the DeCSS source code was leaked, Fawcus noticed that DeCSS included his css-auth code in violation of the GNU GPL. When Johansen was made aware of this, he contacted Fawcus to solve the issue and was granted a license to use the code in DeCSS under non-GPL terms. The GNU logo The GNU General Public License (GNU GPL or simply GPL) is a widely-used free software license, originally written by Richard Stallman for the GNU project. ...

Johansen was involved in a flamewar with another member on livid-dev over the GPL violation issue. Johansen was a FreeBSD supporter and criticized Linux. The main point of the dispute was that Johansen claimed that he had been granted a non-GPL license by Fawcus for the css-auth code, while the other party claimed that he was lying. The flamewar ended when Fawcus confirmed Johansen's side of the story.^[3] At the end of 2000, a document written by an anonymous author surfaced on the Internet.^[4] It accuses Johansen of lying, slandering Linux and violating the GPL. One of the document's claims is that UDF support was not an issue under Linux. This is disputed by Matthew Pavlovich, LiViD project leader, who testified in Universal v. Reimerdes that UDF under Linux was an issue.^[5] Look up flaming in Wiktionary, the free dictionary. ... FreeBSD is a Unix-like free operating system descended from AT&T UNIX via the Berkeley Software Distribution (BSD) branch through the 386BSD and 4. ... Linux (IPA pronunciation: ) is a Unix-like computer operating system. ... 2000 (MM) was a leap year starting on Saturday of the Gregorian calendar. ... This article needs to be cleaned up to conform to a higher standard of quality. ... The Universal Disk Format (UDF) is a format specification of a file system for storing files on optical media. ...

On January 23, 2004, the DVD CCA dropped the case against Jon Johansen.^[6] January 23 is the 23rd day of the year in the Gregorian calendar. ... shelby was here 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... The DVD Copy Control Association (DVD CCA) is an organization primarily responsible for the copy prevention of DVDs. ...

Jon Lech Johansen's involvement

The DeCSS program was a collaborative project, in which Jon wrote the Graphical User Interface. The transcripts from the appeals court (Borgarting lagmannsrett), published in the Norwegian newspaper Verdens Gang, contain the following description of the process which led to the release of DeCSS:^[7] A graphical user interface (GUI) is a type of user interface which allows people to interact with a computer and computer-controlled devices which employ graphical icons, visual indicators or special graphical elements called widgets, along with text labels or text navigation to represent the information and actions available to... Verdens Gang, commonly known as VG, is Norways largest newspaper with a circulation of 365 000 copies in 2004. ...

Through Internet Relay Chat (henceforth IRC), [Jon Lech Johansen] made contact with like-minded [people seeking to develop a DVD-player under the Linux operating system]. September 11, 1999, he had a conversation with "mdx" about how the encryption algorithm in CSS could be found, by using a poorly secured software-based DVD-player. In a conversation [between Jon Lech Johansen and "mdx"] September 22, "mdx" informs that "the nomad" had found the code for CSS decryption, and that "mdx" now would send this [code] to Jon Lech Johansen. "The nomad" allegedly found this decryption algorithm through so-called reverse engineering of a Xing DVD-player, where the [decryption] keys were more or less openly accessible. Through this, information that made it possible [for "mdx"] to create the code CSS_scramble.cpp was retrieved. From chat logs dated November 4, 1999 and November 25, 1999, it appears that "the nomad" carried through the reverse engineering process on a Xing player, which he characterized as illegal. As the case is presented for the High Court, this was not known by Jon Lech Johansen before November 4 [1999].

Regarding the authentication code, the High Court takes for its basis that "the nomad" obtained this code through the electronic mailing list LiVid (Linux Video) on the internet, and that it was created by Derek Fawcus. It appears through a LiVid posting dated October 6, 1999 that Derek Fawcus on this date read through the DeCSS source code and compared it with his own. Further, it appears that "the creators [of DeCSS] have taken [Derek Fawcus' code] almost verbatim - the only alteration was the removal of [Derek Fawcus'] copyright header and a paragraph containing commentaries, and a change of the function names." The name [of the code] was CSS_auth.cpp.

The High Court takes for its basis that the program Jon Lech Johansen later programmed, the graphical user interface, consisted of "the nomad's" decryption algorithm and Derek Fawcus' authentication package. The creation of a graphical user interface made the program accessible, also for users without special knowledge in programming. The program was published on the internet for the first time October 6, 1999, after Jon Lech Johansen had tested it on the movie "The Matrix." In this, he downloaded approximately 2.5%. 200 megabytes, of the movie to the hard drive on his computer. This file is the only film fragment Jon Lech Johansen has saved on his computer. Linux (IPA pronunciation: ) is a Unix-like computer operating system. ... September 11 is the 254th day of the year in the Gregorian calendar (255th in leap years). ... Year 1999 (MCMXCIX) was a common year starting on Friday (link will display full 1999 Gregorian calendar). ... September 22 is the 265th day of the year (266th in leap years) in the Gregorian calendar. ... Reverse engineering (RE) is the process of taking something (a device, an electrical component, a software program, etc. ... November 4 is the 308th day of the year (309th in leap years) in the Gregorian calendar. ... Year 1999 (MCMXCIX) was a common year starting on Friday (link will display full 1999 Gregorian calendar). ... is the 329th day of the year (330th in leap years) in the Gregorian calendar. ... Year 1999 (MCMXCIX) was a common year starting on Friday (link will display full 1999 Gregorian calendar). ... November 4 is the 308th day of the year (309th in leap years) in the Gregorian calendar. ... October 6 is the 279th day of the year (280th in leap years). ... Year 1999 (MCMXCIX) was a common year starting on Friday (link will display full 1999 Gregorian calendar). ... October 6 is the 279th day of the year (280th in leap years). ... Year 1999 (MCMXCIX) was a common year starting on Friday (link will display full 1999 Gregorian calendar). ...

Technology and derived works

See also: libdvdcss

When the release of the DeCSS source code made the CSS algorithm available for public scrutiny, it was soon found to be susceptible to a brute force attack quite different from DeCSS. The encryption is only 40-bit, and does not use all keys; a high-end home computer (as of 1999) running optimized code is able to brute-force it in 24 hours quite easily. libdvdcss is a free, highly portable library for accessing and unscrambling DVDs encrypted with the Content Scramble System. ... The EFFs US$250,000 DES cracking machine contained over 1,800 custom chips and could brute force a DES key in a matter of days — the photograph shows a DES Cracker circuit board fitted with several Deep Crack chips. ... 40-bit encryption is a key size for symmetric encryption representing a low-level of security where the key is forty bits in length (five bytes). ...

Programmers around the world created hundreds of programs equivalent to DeCSS, some merely to demonstrate the trivial ease with which the system could be bypassed, and others to add DVD support to open source movie players. The licensing restrictions on CSS make it impossible to create an open source implementation through official channels, and closed source drivers are unavailable for some operating systems, so some users need DeCSS to watch movies. Open source refers to projects that are open to the public and which draw on other projects that are freely available to the general public. ...

In early 2000, a program with the same name but a very different purpose (removing Cascading Style Sheets tags from HTML code) was also developed. People were encouraged to mirror the website of this unrelated program, as a means of presumably making it more difficult for anti-DeCSS agents to find the 'real' DeCSS program.[1] 2000 (MM) was a leap year starting on Saturday of the Gregorian calendar. ... In computing, Cascading Style Sheets (CSS) is a stylesheet language used to describe the presentation of a document written in a markup language. ...

Legal response

The chief complaints against DeCSS (and similar programs) is that once the unencrypted source video is available in digital form, it can be copied without degradation, so DeCSS can be used for copyright infringement. However, lossless digital image copying of DVDs without decrypting them was already widespread before DeCSS, especially in East Asia. Furthermore, various DVD backup utilities that made use of "licensed" CSS decoding routines were also widely available.

In protest against legislation that prohibits publication of copy protection circumvention code in countries that implement the WIPO Copyright Treaty (such as the United States' Digital Millennium Copyright Act), some have devised clever ways of distributing descriptions of the DeCSS algorithm, such as through steganography, through various Internet protocols, on t-shirts and in dramatic readings, as MIDI files, as a series of haiku poems,^[8] and even as a so-called illegal prime number. However, the CSS algorithm seems to require more characters to describe in a computer programming language than the RC4 algorithm by RSA Data Security; one of the shortest implementations of the RC4 cipher (called "efdtt") is 434 bytes. Because of this, it has not been distributed by some of the more "inventive" methods used to distribute the RSA algorithm during the days of ITAR — it is not suitable for tattoos, email signatures, etc. The WIPO Copyright Treaty, adopted by the World Intellectual Property Organization (WIPO) in 1996, provides additional protections for copyright deemed necessary in the modern information era. ... The Digital Millennium Copyright Act (DMCA) is a United States copyright law which implements two 1996 WIPO treaties. ... Steganography is the art and science of writing hidden messages in such a way that no one apart from the intended recipient knows of the existence of the message; this is in contrast to cryptography, where the existence of the message itself is not disguised, but the content is obscured. ... Musical Instrument Digital Interface, or MIDI, is a system designed to transmit information between electronic musical instruments. ... Haiku )   is a mode of Japanese poetry, the late 19th century revision by Masaoka Shiki of the older hokku ), the opening verse of a linked verse form, haikai no renga. ... An illegal prime is a prime number which contains information forbidden by law to possess or distribute. ... In cryptography, RC4 (also known as ARC4 or ARCFOUR) is the most widely-used software stream cipher and is used in popular protocols such as Secure Sockets Layer (SSL) (to protect Internet traffic) and WEP (to secure wireless networks). ... In cryptology, RSA is an algorithm for public-key encryption. ... In cryptology, RSA is an algorithm for public-key encryption. ... International Traffic in Arms Regulations (ITAR) is a set of United States government regulations that control the export and import of defense-related articles and services on the United States Munitions List. ... A signature block (often abbreviated as signature, sig block, sig file, or just sig) is a block of text automatically appended at the bottom of an e-mail message, Usenet article, or forum post. ...

The first legal threats against sites hosting DeCSS, and the beginning of the DeCSS mirroring campaign, began in about early November 1999 (Universal v. Reimerdes). As a response to these threats a program also called DeCSS but with an unrelated function was developed.^[9] This program can be used for stripping Cascading Style Sheets tags from an HTML page. In one case, a school removed a student's webpage that included a copy of this program, mistaking it for the original DeCSS program, and received a great deal of negative media attention. The CSS stripping program had been specifically created to bait the MPAA in this manner.^[10] Year 1999 (MCMXCIX) was a common year starting on Friday (link will display full 1999 Gregorian calendar). ... This article needs to be cleaned up to conform to a higher standard of quality. ... In computing, Cascading Style Sheets (CSS) is a stylesheet language used to describe the presentation of a document written in a markup language. ... HTML, short for Hypertext Markup Language, is the predominant markup language for the creation of web pages. ...

As of 2007, DeCSS and several clones (which have not been specifically brought to court) can be readily obtained over the Internet. Some Linux distributions are able to install a DVD player incorporating a CSS implementation with a single command. Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era. ... A Linux distribution, often simply distribution or distro, is a member of the Linux family of Unix-like operating systems comprising the Linux kernel, the non-kernel parts of the GNU operating system, and assorted other software. ... The inside of a DVD player A DVD player is a device not only playing discs produced under the DVD Video standard but also playing discs under the standard of DVD Audio. ...

External links

• Gallery of CSS Descramblers (David S. Touretzky)
• DeCSS Central - Information about DVD, CSS, DeCSS, LiVid, the DVD CCA and MPAA and the various lawsuits surrounding DeCSS.
• 2600 News: DVD Industry Takes 2600 to Court
• Aftenposten: Prosecutors let DVD-Jon's victory stand
• The Openlaw DVD/DeCSS Forum Frequently Asked Questions (FAQ) List
• DeCSS Haiku - How to decrypt a DVD - in Haiku form - by Seth Schoen
• The history of the DeCSS Haiku, by Seth Schoen
• 42 ways to distribute DeCSS
• DeCSS Explained - A technical overview of the CSS decryption algorithm.
• DVD-9 to 5: The New Copying Reality by Hugh Bennett
• DeCSS.c, The DeCSS source code

Image File history File links This is a lossless scalable vector image. ... Dr. David S. Touretzky is a research professor in the Computer Science Department and the Center for the Neural Basis of Cognition at Carnegie Mellon University. ...

References

1. ^ The Truth about DVD CSS cracking; November 4, 1999. Retrieved on January 4, 2007.
2. ^ The Truth about DVD CSS cracking; November 4, 1999. Retrieved on January 4, 2007.
3. ^ Derek Fawcus ending liviv-dev flamewar by confirming Johansen's side of the story.
4. ^ http://www.trust-us.ch/decss/decsstruth.txt. Retrieved on December 5, 2005.
5. ^ Transcript of Trial - Day 5, MPAA v. 2600 NY; July 21, 2000. Retrieved on December 5, 2005.
6. ^ EFF: DVD Descrambling Code Not a Trade Secret. Retrieved on December 5, 2005.
7. ^ http://www.vg.no/pub/vgart.hbs?artid=206926
8. ^ http://www-2.cs.cmu.edu/~dst/DeCSS/Gallery/decss-haiku.txt. Retrieved on December 5, 2005.
9. ^ Pigdog Journal - DeCSS Distribution Center. Retrieved on May 28, 2007.
10. ^ Pigdog Journal - DeCSS Distribution Center. Retrieved on May 28, 2007.