AACS encryption key controversy

From Wikipedia, the free encyclopedia

Jump to: navigation, search

The AACS encryption key controversy, also known as the AACS cryptographic key controversy and the HD DVD encryption key controversy, arose in April 2007 when the Motion Picture Association of America and the Advanced Access Content System Licensing Administrator, LLC (AACS LA) began issuing demand letters[1] to websites publishing a 128-bit number, represented in hexadecimal as 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0[2][3] (commonly referred to as 09 F9[4][5]), which is one of the cryptographic keys for HD DVDs and Blu-ray Discs. The letters demanded the immediate removal of the key and any links to it, citing the anti-circumvention provisions of the U.S. Digital Millennium Copyright Act (DMCA).

In response to widespread Internet postings of the key, the AACS LA issued various press statements, praising those websites that complied with their requests as acting in a "responsible manner", warning that "legal and technical tools" were adapting to the situation.

The controversy was further escalated in early May 2007, when aggregate news site Digg received a DMCA cease and desist notice and then removed numerous articles on the matter and banned users reposting the information.[6] This sparked what some describe as a digital revolt,[7] or "cyber-riot",[8] in which users posted and spread the key on Digg, and throughout the Internet en masse. The AACS LA described this situation as an "interesting new twist".[9]


[edit] Background

Hexadecimal is a base-16 numeral system used in the fields of computer programming and mathematics. The key is an ordinary number most widely known by its hexadecimal representation; in decimal notation, it is 13,256,278,887,989,457,651,018,865,901,401,704,640[10].

Because the encryption key may be used as part of circumvention technology forbidden by the DMCA, its possession and distribution has been viewed by the AACS, as well as some law professors, as illegal.[1][11] Since it is a 128-bit numerical value, it was dubbed an illegal number.[12][13][14] Opponents to the expansion of the scope of copyright criticize the idea of making a particular number illegal.[15]

Commercial HD DVDs and Blu-ray Discs integrate copy protection technology specified by the AACS LA. There are several interlocking encryption mechanisms, such that cracking one part of the system does not necessarily crack other parts. Therefore, the "09 F9" key is only one of many parts that is needed to play a disc on an unlicensed player.

The AACS system can be used to revoke a key of a specific playback device, after it is known to have been compromised, as it has for WinDVD.[16] The compromised players can still be used to view old discs, but not newer releases without encryption keys for the compromised players. If other players are then cracked, further revocation would lead to legitimate users of compromised players being forced to upgrade or replace their player software or firmware in order to view new discs. Each playback device comes with a binary tree of secret device and processing keys. The processing key in this tree, a requirement to play the AACS encrypted discs, is selected based on the device key and the information on the disc to be played. As such, a processing key such as the "09 F9" key is not revoked, but newly produced discs cause the playback devices to select a different valid processing key to decrypt the discs.[17]

[edit] Timeline of AACS cracking

[edit] 2006

On 26 December 2006, a person using the alias muslix64 published a utility named BackupHDDVD and its source code on the DVD decryption forum at the website Doom9.[18] BackupHDDVD can be used to decrypt AACS protected content once one knows the encryption key.[19] muslix64 claimed to have found title and volume keys in main memory while playing HD DVD discs using a software player, and that finding them is not difficult.[20]

[edit] 2007

On 2 January 2007, muslix64 published a new version of the program, with volume key support.[21] On 12 January 2007, other forum members detailed how to find other title and volume keys, stating they had also found the keys of several movies in RAM while running WinDVD.

On or about 13 January, a title key was posted on pastebin.com in form of a riddle, which was solved by entering terms into the Google search engine. By converting these results to hexadecimal, a correct key could be formed.[22] Later that day, the first cracked HD DVD, Serenity, was uploaded on a private torrent tracker.[23] The AACS LA confirmed on January 26 that the title keys on certain HD DVDs had been published without authorization.[24]

Doom9.org forum user arnezami found and published the "09 F9" AACS processing key on February 11:[25]

Nothing was hacked, cracked or even reverse engineered btw: I only had to watch the "show" in my own memory. No debugger was used, no binaries changed.

This key is not specific to any playback device or DVD title. Doom9.org forum user jx6bpm claimed on March 4 to have revealed CyberLink's PowerDVD's key, and that it was the key in use by AnyDVD.[26]

The AACS LA announced on April 16 that it had revoked the decryption keys associated with certain software high-definition DVD players, which will not be able to decrypt AACS encrypted disks mastered after 23 April, without an update of the software.[27][28]

On May 17, one week before any discs with the updated processing key had reached retail, claims were reported of the new keys having been retrieved from a preview disc of The Matrix Trilogy.[29] On May 23, the key 45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2 was posted on Edward Felten's Freedom to Tinker Blog[30] and confirmed a week later by arnezami on Doom9 as the new processing key.[31]

[edit] 2008

In August, F1 90 A1 E8 17 8D 80 64 34 94 39 4F 80 31 D9 C8 --- MKB v4 decryption key was posted, as well as 7A 5F 8A 09 F8 33 F7 22 1B D4 1F A6 4C 9C 79 33 --- which appeared to work with MKB v6, MKB v7 and MKB v8 discs.[32]

[edit] 2009

In March, C8 72 94 CE 84 F9 CC EB 59 84 B5 47 EE C1 8D 66 --- MKB v9 and 45 2F 6E 40 3C DF 10 71 4E 41 DF AA 25 7D 31 3F --- MKB v10 decryption keys were posted.[33]

[edit] DMCA notices and Digg

Screenshot of the Digg front page during the user revolt; every story is related to the HD DVD key.

As early as 17 April 2007, AACS LA had issued DMCA violation notices, sent by Charles S. Sims of Proskauer Rose.[34][35] Following this, dozens of notices were sent to various websites hosted in the United States.[36]

On 1 May 2007, in response to a DMCA demand letter, technology news site Digg began closing accounts and removing posts containing or alluding to the key. The Digg community reacted by creating a flood of posts containing the key, many using creative ways of semi-directly or indirectly inserting the number, such as in song or images (either representing the digits pictorially or directly representing bytes from the key as colors) or on merchandise.[37] At one point, Digg's "entire homepage was covered with links to the HD-DVD code or anti-Digg references."[38] Eventually the Digg administrators reversed their position, stating:

But now, after seeing hundreds of stories and reading thousands of comments, you’ve made it clear. You’d rather see Digg go down fighting than bow down to a bigger company. We hear you, and effective immediately we won’t delete stories or comments containing the code and will deal with whatever the consequences might be.[39][40][41]

[edit] Legal opinions

Lawyers and other representatives of the entertainment industry, including Michael Avery, an attorney for Toshiba Corporation, expressed surprise at Digg's decision, but suggested that a suit aimed at Digg might merely spread the information more widely.

If you try to stick up for what you have a legal right to do, and you're somewhat worse off because of it, that's an interesting concept.[42]

The American Bar Association's eReport published a discussion of the controversy,[43] in which Eric Goldman at Santa Clara University's High Tech Law Institute noted that the illegality of putting the code up is questionable (that Section 230 of the Communications Decency Act may protect the provider when the material itself is not copyrighted), although continuing to allow posting of the key may be "risky", and entertainment lawyer Carole Handler noted that even if the material is illegal, laws such as the DMCA may prove ineffective in a practical sense.

[edit] Impact

In a response to the events occurring on Digg and the call to "Spread this number", the key was rapidly posted to thousands of pages, blogs and wikis across the Internet.[44][45] The reaction has been likened to the Streisand effect; when attempts to censor the key were made by Digg management in response to DMCA notices, people reacted by posting the encryption key en masse.[46]

Internet users began circulating versions of this image, calling it a Free Speech Flag, in blog posts on dozens of websites and as user avatars on forums such as Digg. The RGB encoding of each of the five colors provides three bytes of the 09 F9 key, with the sixteenth byte "C0" appended in the lower right corner.[47]

Intellectual property lawyer Douglas J. Sorocco noted, "People are getting creative. It shows the futility of trying to stop this. Once the information is out there, cease-and-desist letters are going to infuriate this community more."[43] Outside of the Internet and the mass media, the key has appeared in or on T-shirts,[11] poetry, songs and music videos,[11] a movie,[11] illustrations and other graphic artworks,[48] tattoos and body art,[49] and comic strips.[50]

On Tuesday afternoon, May 1, 2007, a Google search for the key returned 9,410 results,[51] while the same search the next morning returned nearly 300,000 results.[3] On Friday, the BBC reported that a search on Google shows almost 700,000 pages have published the key,[9] despite the fact that on April 17, the AACS LA sent a DMCA notice to Google, demanding that Google stop returning any results for searches for the key.[52][53]

Widespread news coverage[54] included speculation on the development of user-driven websites,[55] the legal liability of running a user-driven website,[56] the perception of acceptance of DRM,[57] the failure as a business model of "secrecy based businesses ... in every aspect" in the Internet era,[58] and the harm an industry can cause itself with harshly-perceived legal action.[59]

In an opposing move, Carter Wood of the National Association of Manufacturers said they had removed the "Digg It"-link from their weblog.[60]

Until the Digg community shows as much fervor in attacking intellectual piracy as attacking the companies that are legitimately defending their property, well, we do not want to be promoting the site by using the "Digg It" feature.

Media coverage initially avoided quoting the key itself. However, several US-based news sources have run stories containing the key, quoting its use on Digg,[61][62][63][64][65][66] though none are known to have received DMCA notices as a result. Later reports have discussed this, quoting the key.[67] Current TV broadcast the key during a Google Current story on the Digg incident on May 3, displaying it in full on screen for several seconds and placing the story on the station website.[68]

[edit] AACS LA reaction

On May 7th of 2007, the AACS LA posted on its website, stating that it had "requested the removal solely of illegal circumvention tools, including encryption keys, from a number of web sites", and that it had "not requested the removal or deletion of any... discussion or commentary". The statement continued, "AACS LA is encouraged by the cooperation it has received thus far from the numerous web sites that have chosen to address their legal obligations in a responsible manner."[69] BBC News earlier quoted an AACS executive saying: Bloggers "crossed the line" and it was looking at "legal and technical tools" to confront those who published the key and that the events involving Digg were an "interesting new twist".[9]

[edit] See also

[edit] References

  1. ^ a b "AACS licensor complains of posted key". Chilling Effects. http://www.chillingeffects.org/notice.cgi?sID=03218. Retrieved on 2007-05-04. 
  2. ^ Rupert Goodwins (11 May 2007). "An interesting sales tactic". ZDNet UK. http://community.zdnet.co.uk/blog/0,1000000567,10005286o-2000331777b,00.htm. Retrieved on 2007-05-18. 
  3. ^ a b Nick Farrell (2 May 2007). "09 f9 [...] is the number they tried to ban". The Inquirer. http://www.theinquirer.net/en/inquirer/news/2007/05/02/09-f9-11-02-9d-74-e3-5b-d8-41-56-c5-63-56-88-c0-is-the-number-they-tried-to-ban. Retrieved on 2007-05-03. 
  4. ^ Fred von Lohmann (2 May 2007). "09 f9: A Legal Primer". EFF. http://www.eff.org/deeplinks/2007/05/09-f9-legal-primer. Retrieved on 2007-05-18. 
  5. ^ Frederick Lane (5 May 2007). "09 F9: An Unlikely Star Is Born Thanks to Digg.com". Sci-Tech Today. http://www.sci-tech-today.com/news/09-F9--An-Unlikely-Star-Is-Born/story.xhtml?story_id=011001CEELPZ. Retrieved on 2007-05-18. 
  6. ^ David Utter (2 May 2007). "Digg Embroiled In HD DVD Controversy". WebProNews. http://www.webpronews.com/insiderreports/2007/05/02/digg-embroiled-in-hd-dvd-controversy. Retrieved on 2007-05-18. 
  7. ^ "Digg revolt over HD DVD codes". news.com.au. 2 May 2007. http://www.australianit.news.com.au/story/0,24897,21659892-27317,00.html. Retrieved on 2007-05-20. 
  8. ^ Michael S. Malone (3 May 2007). "The First Amendment vs. Patents in Web 2.0". 6abc. http://abclocal.go.com/wpvi/story?section=news/technology&id=5269200. Retrieved on 2007-05-20. 
  9. ^ a b c Darren Waters (4 May 2007). "DRM group vows to fight bloggers". BBC. http://news.bbc.co.uk/2/hi/technology/6623331.stm. Retrieved on 2007-05-04. 
  10. ^ Read as: "thirteen undecillion, two hundred and fifty-six decillion, two hundred and seventy-eight nonillion, eight hundred and eighty-seven octillion, nine hundred and eighty-nine septillion, four hundred and fifty-seven sextillion, six hundred and fifty-one quintillion, eighteen quadrillion, eight hundred and sixty-five trillion, nine-hundred and one billion, four hundred and one million, seven hundred and four thousand, six hundred and forty"
  11. ^ a b c d Stone, Brad (2007-05-02). "In Web Uproar, Antipiracy Code Spreads Wildly". The New York Times. http://www.nytimes.com/2007/05/03/technology/03code.html. Retrieved on 2007-05-03. 
  12. ^ Blogger News Network / ‘Illegal Number’ Triggers Flood of MPAA Cease-and Desist Letters
  13. ^ ButtUgly: Main_blogentry_010507_1
  14. ^ Protected Blog Login « WordPress.com
  15. ^ Edward Felten (May 3, 2007). "Why the 09ers Are So Upset". Freedom to Tinker. http://freedom-to-tinker.com/node/1154. Retrieved on 2007-01-08. 
  16. ^ Ken Fisher (26 January 2007). "AACS key revoked". Ars Technica. http://arstechnica.com/news.ars/post/20070126-8710.html. Retrieved on 2007-05-02. 
  17. ^ Hal Finney (03 May 2007). "Hal Finney on 'AACS and Processing Key'". https://financialcryptography.com/mt/archives/000908.html. Retrieved on 2007-05-18. 
  18. ^ Muslix64 (26 December 2006). "BackupHDDVD, a tool to decrypt AACS protected movies". Doom9's Forum. http://forum.doom9.org/showthread.php?t=119871. Retrieved on 2007-04-09. 
  19. ^ Intel Corporation; International Business Machines Corporation, Matsushita Electric Industrial Co., Ltd., Microsoft Corporation, Sony Corporation, Toshiba Corporation, The Walt Disney Company, Warner Bros. (2006-07-25). "Advanced Access Content System (AACS)" (PDF). http://www.aacsla.com/specifications/AACS_Spec_HD_DVD_Recordable_0.921_20060725.pdf. Retrieved on 2007-04-09. 
  20. ^ "HD DVD Content Protection already hacked?". TechAmok. 2006-12-28. http://www.techamok.com/?pid=1849. Retrieved on 2007-01-02. 
  21. ^ Muslix64 (2 January 2007). "BackupHDDVD, a tool to decrypt AACS protected movies". http://forum.doom9.org/showpost.php?s=61e391f4db570e16e4f05a98ffa97f6d&p=924731&postcount=245. Retrieved on 2007-04-09. 
  22. ^ "kad77" (13 January 2007). "Decryption Keys For HD-DVD Found, Confirmed". Slashdot. http://it.slashdot.org/article.pl?sid=07/01/13/181222. Retrieved on 2007-04-09. 
  23. ^ Reimer, Jeremy (2007-01-15). "First pirated HD DVD movie hits BitTorrent". Ars Technica. http://arstechnica.com/news.ars/post/20070115-8622.html. 
  24. ^ "Hi-def DVD security is bypassed". BBC. 26 January 2007. http://news.bbc.co.uk/1/hi/technology/6301301.stm. Retrieved on 2007-01-26. 
  25. ^ arnezami (11 February 2007). "Processing Key, Media Key and Volume ID found!!!". Doom9's Forum. http://forum.doom9.org/showthread.php?p=952954#post952954. Retrieved on 2007-05-04. 
  26. ^ jx6bpm (3 March 2007). "PowerDVD private key". Doom9's Forums. http://forum.doom9.org/showthread.php?p=965425#post965425. Retrieved on 2007-04-09. 
  27. ^ "HD DVD, Blu-ray protection in question after attacks". Yahoo. 16 April 2007. http://tech.yahoo.com/news/infoworld/20070416/tc_infoworld/87720. Retrieved on 2007-05-01. 
  28. ^ Rick Merritt (2007-05-03). "The real casualty in high def DVD revolt". EETimes. http://www.eetimes.com/news/latest/showArticle.jhtml?articleID=199203754. Retrieved on 2007-05-05. 
  29. ^ Ryan Paul (2007-05-17). "Latest AACS revision defeated a week before release". Arstechnica. http://arstechnica.com/news.ars/post/20070517-latest-aacs-revision-defeated-a-week-before-release.html. Retrieved on 2007-05-17. 
  30. ^ BtCB (2007-05-23). "You Can Own An Integer Too". Freedom to Tinker. http://freedom-to-tinker.com/node/1155#comment-367359. Retrieved on 2007-05-30. 
  31. ^ arnezami (2007-05-30). "New Processing Key found!! (MKB v3 is now open)". Doom9's Forum. http://forum.doom9.org/showthread.php?p=1008940. Retrieved on 2007-05-30. 
  32. ^ KenD00 (2008-08-08). "MKBv4 and MKBv6, MKBv7, MKBv8 Processing Keys found". Doom9's Forum. http://forum.doom9.org/showthread.php?t=140169. Retrieved on 2009-04-12. 
  33. ^ KenD00 (2009-03-20). "MKBv9 and MKBv10 Processing Keys found". Doom9's Forum. http://forum.doom9.org/showthread.php?t=145789. Retrieved on 2009-04-12. 
  34. ^ Davies, Greg (3 May 2007). "The Aftermath of the Digg Revolt: What now?". TheTrukstoP.com. http://www.the-trukstop.com/articles/2007/aftermath_of_digg_revolt.html. Retrieved on 2007-05-03. 
  35. ^ "DMCA Takedown Notice". 17 April 2007. http://www.chillingeffects.org/anticircumvention/notice.cgi?NoticeID=7180. Retrieved on 2007-05-02. 
  36. ^ "AACS Takedowns Backfire". 1 May 2007. http://www.tgdaily.com/content/view/31859/97/. Retrieved on 2007-05-02. 
  37. ^ "Digg.com Attempts To Suppress HD-DVD Revolt". Slashdot. 1 May 2007. http://yro.slashdot.org/article.pl?sid=07/05/02/0235228. Retrieved on 2007-05-02. 
  38. ^ Andy Greenberg (May 02, 2007), Digg's DRM Revolt, Forbes, http://www.forbes.com/technology/2007/05/02/digital-rights-management-tech-cx_ag_0502digg.html 
  39. ^ Kevin Rose (2007-05-01). "Digg This: 09 F9 [...]". Digg the Blog. Digg Inc. http://blog.digg.com/?p=74. Retrieved on 2007-05-02. 
  40. ^ "DVD DRM row sparks user rebellion". BBC. 2 May 2007. http://news.bbc.co.uk/2/hi/technology/6615047.stm. Retrieved on 2007-05-02. 
  41. ^ Marcus Yam (May 2, 2007), AACS Key Censorship Leads to First Internet Riot, http://www.dailytech.com/aacs+key+censorship+leads+to+first+internet+riot/article7129.htm 
  42. ^ Alex Pham; Joseph Menn (3 May 2007). "User rebellion at Digg.com unearths a can of worms". Los Angeles Times (latimes.com). http://articles.latimes.com/2007/may/03/business/fi-revolt3. Retrieved on 2007-05-04. 
  43. ^ a b Stephanie Francis Ward (May 11, 2007). "It’s No Secret: Code Stirs Up a Web Storm: Lawyers question whether Web site can be forced to remove posts". ABA [[eReport (ABA)|]]. http://www.abanet.org/journal/ereport/my11blog.html. Retrieved on 2007-05-11. [dead link]
  44. ^ "Spread this number". 30 April 2007. http://rudd-o.com/archives/2007/04/30/spread-this-number/. Retrieved on 2007-05-02. 
  45. ^ Tim Starling (2 May 2007). "HD DVD key and the spam blacklist". WikiEN-L mailing list. http://lists.wikimedia.org/pipermail/wikien-l/2007-May/070489.html. Retrieved on 2007-05-04. 
  46. ^ Mike Masnick. "AACS Discovers The Streisand Effect: The More You Try To Suppress Something, The More Attention It Gets". http://techdirt.com/articles/20070501/202154.shtml. Retrieved on 2007-05-03. 
  47. ^ John Marcotte (1 May 2007). "Free Speech Flag". Badmouth.net. http://www.badmouth.net/free-speech-flag/. Retrieved on 2007-05-03. 
  48. ^ "Photoshop Rebels Rip Great HD DVD Clampdown". Wired News. 2007-05-03. http://www.wired.com/entertainment/hollywood/multimedia/2007/05/crackkdown_protest. Retrieved on 2007-05-03. 
  49. ^ "AACS LA: Internet "revolt" be damned, this fight is not over". Ars Technica. 2007-05-04. http://arstechnica.com/news.ars/post/20070504-aacs-la-internet-revolt-be-damned-this-fight-is-not-over.html. Retrieved on 2007-05-04. 
  50. ^ Stevens, R. (2007-05-10). "Kill Me Three Times, Shame On Rasputin". Diesel Sweeties. http://www.dieselsweeties.com/archive.php?s=1744. Retrieved on 2007-05-10. 
  51. ^ Thomas Claburn (2 May 2007). "HD DVD Blu-Ray Decryption Key Widely Posted Online". Information Week. Dark Reading. http://www.darkreading.com/document.asp?doc_id=123127&WT.svl=cmpnews1_1. Retrieved on 2007-05-03. [dead link]
  52. ^ Mann, Justin (2007-05-01). "AACS LA tells Google to stop indexing hack - or else". TechSpot. http://www.techspot.com/news/25130-aacs-la-tells-google-to-stop-indexing-hack--or-else.html. Retrieved on 2007-05-05. 
  53. ^ "AACS licensor complains of posted key". Chilling Effects. 2007-04-17. http://www.chillingeffects.org/notice.cgi?sID=03218. Retrieved on 2007-05-05. 
  54. ^ Forbes, CNet, BBC, Financial Times, Associated Press[dead link]
  55. ^ Verne Kopytoff. "User revolt at Digg.com shows risks of Web 2.0". http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2007/05/03/MNG4RPK18J1.DTL. Retrieved on 2007-05-03. 
  56. ^ Tom Spring. "Mob's Win is Digg's Loss". http://blogs.pcworld.com/staffblog/archives/004292.html. Retrieved on 2007-05-03. 
  57. ^ John Carroll. "A Digg riot and AACS". http://blogs.zdnet.com/carroll/?p=1685. Retrieved on 2007-05-03. 
  58. ^ It’s No Secret: Code Stirs Up a Web Storm[dead link]
  59. ^ Dvorak, John C. (2007-05-03). "Digg's DVD-decoder fiasco: Lawyers' efforts can be counterproductive". Dow Jones MarketWatch. 
  60. ^ Carter Wood (2007-05-03). "Intellectual Property Dust-Up: Digg". http://www.shopfloor.org/2007/05/03/intellectual-property-dust-up-digg/. Retrieved on 2008-08-07. 
  61. ^ Buchanan, Matt (2007-05-02). "Breaking: Digg Riot in Full Effect Over Pulled HD-DVD Key Story". Gizmodo. http://gizmodo.com/gadgets/geeks-will-not-be-silenced/breaking-digg-riot-in-full-effect-over-pulled-hd+dvd-key-story-256982.php. Retrieved on 2007-05-04. 
  62. ^ Berger, Adam (2007-05-02). "HD-DVD cracked, Digg users causes an uproar". Gadgetell. http://www.gadgetell.com/tech/comment/hd-dvd-cracked-digg-users-causes-an-uproar/. Retrieved on 2007-05-04. 
  63. ^ Beal, Andy (2007-05-02). "Rose Hands Over Digg Control". WebProNews. http://www.webpronews.com/blogtalk/2007/05/02/rose-hands-over-digg-control. Retrieved on 2007-05-04. 
  64. ^ Lane, Frederick (2007-05-02). "Digg This: Web 2.0, Censorship 0". Newsfactor.com. http://www.newsfactor.com/news/Digg-This--Web-2-0--Censorship-0/story.xhtml?story_id=0020006M7M5U. Retrieved on 2007-05-04. 
  65. ^ Singel, Ryan (2007-05-03). "HD DVD Battle Stakes Digg Against Futility of DRM". Wired News. http://www.wired.com/entertainment/hollywood/news/2007/05/digglegal. Retrieved on 2007-05-03. 
  66. ^ Zuckerman, Ethan (2007-05-03). "Does The Number have a lesson for human rights activists?". Worldchanging. http://www.worldchanging.com/archives/006626.html. Retrieved on 2007-05-05. 
  67. ^ Newitz, Annalee (23-29 May 2007). "Number game". Metroactive. http://www.metroactive.com/metro/05.23.07/work-0721.html. Retrieved on 2007-05-24. 
  68. ^ Conor Knighton (2007-05-03). "Can You Digg It?". http://www.current.tv/google/GC03104. Retrieved on 2007-05-05. [dead link]
  69. ^ "Home : AACS - Advanced Access Content System<". AACS LA. http://www.aacsla.com/. Retrieved on 2007-05-10. 

[edit] External links

Personal tools