298:
software to a more secure version, thereby limiting the scope of the compromise each time an exploit is discovered. While a compromised device or processing key could be used to decrypt a large number of discs, BackupHDDVD does not use these keys because they can be revoked by AACS LA. Because the AACS revocation system works by preventing a given device or player from calculating a valid volume unique key, BackupHDDVD circumvents the system entirely by relying on volume or title keys leaked from authorized players. With these keys BackupHDDVD is not subject to device revocation and is able to decrypt the content directly, bypassing the key exchange and verification process.
347:, and mainstream media has ranged from supportive to intensely hostile. By some, the circumvention of AACS was seen as a reaffirmation of fair use. Others felt that the utility was no more than a piracy tool and would bring about group punishment against consumers in the form of player revocation. One article compared proponents of BackupHDDVD to terrorists. When the release of the tool was first publicized, several articles claimed that AACS had been cracked. In fact no cryptographic weaknesses constituting a crack have yet been found in
294:
key. The volume unique key for any disc can be calculated by all authorized devices using another key called a processing key, which is derived from a media key block stored on each disc. Authorized devices use one or more of the manufacturer's assigned device keys to decrypt the media key block, yielding a processing key and enabling further decryption of the volume and title keys, and finally the content.
29:
276:
184:, the underling cryptographic cipher used by AACS. Using this technique, BackupHDDVD is able to completely bypass the AACS chain of trust, rendering it immune to revocation. The cost of this immunity is that users are forced to rely on keys leaking from commercial player software to use BackupHDDVD with new discs.
176:
Muslix64, BackupHDDVD is distributed with none of the cryptographic keys necessary for decryption. Users wanting to use the software to decrypt a protected disc's contents must obtain the appropriate keys separately, a task with which neither the original author nor his or her versions of BackupHDDVD
297:
If a device key is to be revoked, the media key blocks on all discs manufactured after the time of revocation are encrypted in a way which does not enable the revoked device to obtain a valid processing key. Users trying to view new content on a revoked player would be forced to upgrade their player
235:
On
January 2, 2007, the author posted the 1.0 version of the BackupHDDVD utility, which included support for the decoding of discs using volume keys. For several weeks following the utility's release no success using the author's key extraction technique was reported. In mid-January 2007, a volume
293:
to device manufacturers. When an AACS protected disc is manufactured, a series of up to 64 keys called title keys are generated and the video content on the disc is encrypted using these keys. The title keys are stored on the disc and themselves encrypted with another key called the volume unique
250:
alleging a violation in late
February. In compliance with the notice, the project was immediately removed. Several versions of BackupHDDVD have been released by individuals other than the original author, including some versions with GUIs and the ability to locate keys on the internet or scan for
388:
The consortium behind the HD DVD format and the studios delivering films on the format did not release an official statement beyond that they were investigating the utility. On
January 24, 2007 AACS LA issued a statement acknowledging that AACS security had been compromised while urging software
228:, a website devoted to DVD backup. The utility's documentation, along with the forum post, contained little information as to how necessary keys could be obtained. The author elaborated in another forum post, claiming that keys could be obtained by exploiting the necessity for them to be held in
322:
technology. New versions work around this limitation by excluding interactive content from decrypted copies. The utility cannot process HD DVD navigation functionality which enables menus, chapters, secondary audio tracks and subtitles, so these features are inaccessible in copies created by
311:, it then decrypts each video file on the disc using the appropriate keys and writes the results to a location specified by the user. Direct file decryption allows the utility's functionality to remain unaffected by device key revocation and its performance unencumbered with AACS overhead.
306:
Users must have either found decryption keys themselves or obtained them elsewhere for most versions of BackupHDDVD to work. The utility reads a text file containing volume or title keys and attempts to find a set of corresponding keys for the inserted disc. Through a standard AES
236:
key was published by another member of the Doom9 forum along with an explanation of the technique used to obtain it. Other forum members quickly discovered keys for different titles. Keys for many discs are now readily available on the internet.
389:
vendors to limit the availability of keys in memory. Beginning with discs manufactured in late April, versions of PowerDVD and WinDVD responsible for leaking keys have been revoked and free updates are available to owners of affected versions.
255:
with a native
Windows GUI is also available. This version supports multiple CPU threads and runs faster than its Java counterparts. While development of BackupHDDVD has ceased, a commercial HD DVD decryption utility called
335:, BackupHDDVD may qualify as a device primarily intended to "circumvent a technological measure that effectively controls access to a work." If identified as such, it would be illegal to use or distribute.
1139:
192:
According to the creator of BackupHDDVD, he or she first set out to circumvent AACS to bypass a restriction in software HD DVD players which reduced the quality of AACS restricted
318:, BackupHDDVD is severely limited in its ability to produce fully functional copies of commercial discs. Early versions were unable to properly decrypt discs which used the
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941:
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851:
438:
323:
BackupHDDVD. Most versions provide no validation for keys and will still attempt to decrypt a disc's contents with an incorrect key, resulting in corrupt files.
199:
video to that of standard definition DVD video or refused to play outright unless an HDCP compliant chain of video hardware was present. At the time only a few
362:
format, but Blu-ray's AACS implementation has since been circumvented using a similar method. However, Blu-ray offers an additional layer of protection called
180:
BackupHDDVD represented the first known successful attack against AACS. The utility circumvents content protection by decrypting video files directly with
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supported HDCP. As a result, configurations that would have allowed high-definition HD DVD viewing in software players were exceptionally rare.
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and documentation was uploaded to a file hosting service. A link to the file was then posted by the utility's creator on the forums of
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software had played in the leaking of volume and title keys. Both companies have since released updates for their player software.
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Initially, it was thought that the compromise of HD DVD's security would entice some studios into adopting the competing
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to allow for the backup or unrestricted viewing of any AACS-protected discs without the need for title or volume keys.
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57:
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377:, which sells the PowerDVD player software, was quick to deny that its software could be used to obtain keys.
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There was some speculation that the player used by the utility's author to obtain keys would be
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On
December 18, 2006, a video which showed BackupHDDVD being used to decrypt and copy the film
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535:
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28:
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220:. Two days after the video was uploaded, the initial version of the utility along with its
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134:
903:
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475:
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351:, the underlying cryptographic system of AACS. Keys are actually obtained through a
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discs, often to enable playback on hardware configurations without full support for
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them in memory automatically. HDDecrypter, a port of BackupHDDVD to
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274:
225:
193:
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The AACS Licensing
Authority (LA) assigns a series of 253 unique
363:
344:
244:
162:
727:"All Blu-ray Disc and HD DVD Encryption Defeated by Single Key"
996:
558:"GeekTech: Want to View HD Content on Your PC? Upgrade Wisely"
229:
33:
Version of BackupHDDVD modified to include a GUI in use on a
331:
Under United States anti-circumvention law created by the
169:
was posted online, but no licence information was given.
1019:"Cyberlink responds to BackupHDDVD crack: It wasn't us"
239:
Further development of BackupHDDVD was being hosted on
90:
64:
697:"HD DVD reportedly cracked, but difficult to verify"
993:"RESPONSE TO REPORTS OF ATTACKS ON AACS TECHNOLOGY"
113:
101:
71:
56:
42:
790:"Understanding AACS (including Subset-Difference)"
498:"Hacker: Blu-ray, HD DVD copy protection cracked"
1140:Digital rights management circumvention software
934:"New AACS cracks cannot be revoked, says hacker"
816:"Introduction and Common Cryptographic Elements"
343:Reaction to the utility by Doom9 forum members,
620:"Hacker Cracks High-Def DVD Encryption System"
588:"The truth behind HDCP and video card support"
528:"Hackers Claim HD DVD Encryption Circumvented"
848:"Studios Take Claims of AACS Crack Seriously"
172:Written by an anonymous programmer using the
8:
21:
1078:"Corel updates WinDVD to stop AACS hackers"
783:
781:
433:
431:
429:
27:
20:
987:
985:
983:
265:compromised AACS processing or media keys
1045:"Studios' DVDs Face a Crack in Security"
757:"Beta Software to Copy HD DVDs Released"
461:
459:
904:"Latest AACS crack 'beyond revocation'"
668:"AACS DRM cracked by BackupHDDVD tool?"
614:
612:
397:
690:
688:
441:. Techtree. 2006-12-28. Archived from
232:to allow playback in player software.
767:from the original on 23 February 2007
7:
874:"HD DVD anti-rip encryption cracked"
648:from the original on 14 January 2007
1025:from the original on 7 January 2007
854:from the original on 1 January 2007
846:Scott M. Fulton, III (2006-12-29).
707:from the original on 3 January 2007
674:from the original on 2 January 2007
439:"Took Eight Days to Crack HD DVD!"
14:
796:from the original on 3 March 2007
598:from the original on 6 April 2007
333:Digital Millennium Copyright Act
216:to a hard drive was uploaded to
1088:from the original on 5 May 2007
944:from the original on 5 May 2007
914:from the original on 7 May 2007
640:Michael O'Connor (2007-01-02).
508:from the original on 9 May 2007
468:"Next-Gen DVD DRM Hacked—Maybe"
496:Robert McMillan (2006-12-29).
466:Gardiner, Bryan (2006-12-29).
381:was silent about the role its
285:Advanced Access Content System
279:Typical AACS decryption chain.
155:Advanced Access Content System
1:
1076:Reimer, Jeremy (2007-04-07).
1017:Richard Lawler (2007-01-02).
1043:Markoff, John (2007-01-01).
995:. 2007-01-24. Archived from
965:. 2007-02-21. Archived from
932:Jeremy Reimer (2007-03-15).
642:"BackupHDDVD v1.00 Released"
526:Gabriel Ikram (2006-12-28).
314:Originally intended to be a
77:1.0.3 (January 25, 2007
755:Mark Hachman (2006-02-14).
556:Tom Mainelli (2006-07-13).
145:versions which aids in the
1161:
902:John Leyden (2007-04-04).
666:Block, Ryan (2006-12-27).
282:
243:until the site received a
872:Tony Smith (2006-12-28).
725:Marcus Yam (2007-02-13).
695:Ken Fisher (2006-12-28).
586:Ken Fisher (2006-02-14).
97:
52:
26:
302:Features and limitations
16:AACS decryption software
788:arnezami (2007-02-17).
263:exists which relies on
153:discs protected by the
280:
79:; 17 years ago
1145:Windows-only freeware
278:
963:"The HD Disc Hacks"
353:side-channel attack
320:in-movie experience
23:
1049:The New York Times
999:on 4 February 2007
291:cryptographic keys
281:
44:Original author(s)
969:on March 16, 2007
884:on 3 January 2007
445:on 4 January 2007
213:Full Metal Jacket
201:computer monitors
165:. The program's
132:computer software
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316:proof of concept
157:. It is used to
103:Operating system
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1021:. Engadget HD.
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197:high definition
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73:Preview release
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406:"BackupHDDVD"
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1090:. Retrieved
1082:Ars Technica
1081:
1071:
1060:. Retrieved
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1027:. Retrieved
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1001:. Retrieved
997:the original
971:. Retrieved
967:the original
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946:. Retrieved
938:Ars Technica
937:
927:
916:. Retrieved
908:The Register
907:
897:
886:. Retrieved
882:the original
878:The Register
877:
867:
856:. Retrieved
850:. BetaNews.
841:
830:. Retrieved
823:the original
809:
798:. Retrieved
769:. Retrieved
760:
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739:. Retrieved
735:the original
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720:
709:. Retrieved
701:Ars Technica
700:
676:. Retrieved
670:. Engadget.
661:
650:. Retrieved
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624:. Retrieved
622:. 2006-12-30
600:. Retrieved
592:Ars Technica
591:
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570:. Retrieved
566:the original
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540:. Retrieved
536:the original
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510:. Retrieved
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476:the original
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443:the original
416:. Retrieved
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296:
288:
238:
234:
211:
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191:
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139:command line
127:
126:
18:
1130:DVD rippers
761:PC Magazine
472:PC Magazine
418:22 November
241:SourceForge
222:source code
205:video cards
167:source code
130:is a small
128:BackupHDDVD
91:[±]
65:[±]
22:BackupHDDVD
1119:Categories
1092:2007-04-15
1062:2023-01-29
1029:2007-01-02
1003:2007-01-31
973:2007-03-18
948:2007-05-05
918:2007-05-05
888:2007-01-02
858:2007-01-02
832:2007-03-22
800:2007-03-18
771:2007-02-20
741:2007-02-16
711:2007-01-02
678:2007-01-02
652:2007-01-02
626:2007-01-02
602:2007-05-04
572:2007-05-04
542:2007-01-02
512:2007-05-08
482:2007-01-02
449:2007-01-02
414:. SoftNews
271:Background
147:decryption
84:2007-01-25
35:Windows XP
1057:0362-4331
814:AACS-LA.
731:DailyTech
532:DailyTech
502:InfoWorld
411:Softpedia
375:Cyberlink
261:AnyDVD HD
62:Non
1111:at Doom9
1086:Archived
1023:Archived
942:Archived
912:Archived
852:Archived
794:Archived
765:Archived
705:Archived
672:Archived
646:Archived
596:Archived
562:PC World
506:Archived
345:bloggers
339:Reaction
327:Legality
177:assist.
120:Freeware
48:Muslix64
371:revoked
360:Blu-ray
309:library
258:Slysoft
218:YouTube
188:History
159:back up
115:License
108:Windows
82: (
1055:
383:WinDVD
230:memory
174:handle
151:HD DVD
88:)
37:system
826:(PDF)
819:(PDF)
393:Notes
379:Corel
226:Doom9
194:1080p
1053:ISSN
420:2017
245:DMCA
203:and
163:HDCP
141:and
364:BD+
349:AES
182:AES
143:GUI
1121::
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253:C
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Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
