Proximity Based Wireless Audio System

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DVD and Blu-ray Details
ECE 477 Multimedia 29 May 2008
Brian Jones Phillip Radke Nick Santana Austin
Yoder
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DVD and Blu-ray Details
History File Format Security / Encryption Regions
/ Programs
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History of the DVD

• LaserDisc
• VCD
• DVD format war
• High Definition format war

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LaserDisc

• 30cm (11.81 in) diameter
• Two analog audio tracks
• Two digital PCM track
• Three play modes
• Constant Angular Velocity
• Constant Linear Velocity
• Constant Angular Acceleration

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VCD

• Standard created in 1993
• Video encoded using MPEG-1
• Audio encoded using MPEG-2

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MMCD

• MultiMedia Compact Disc
• Announced in May 1994
• Backed by Philips and Sony
• 4.7GB capacity single layer. 7.4GB dual

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SD

• Super Density Disc
• Supported by Toshiba, Time-Warner, Matsushita
  Electric, Hitachi, Mitsubishi Electric, Pioneer,
  Thomson, and JVC.
• 5GB capacity single layer. 10GB dual

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DVD

• Used Toshiba's SD for thinness and high density
• Used Sony's data coding methods that were more
  resiliant to scratches and fingerprints
• 650nm wavelength laser diode
• Storage capacity varies between 4.7GB and 17GB

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HD-DVD vs Blu-Ray

• Both emerged between 2000 and 2002
• Sony was behind Blu-Ray
• Toshiba was behind HD-DVD
• February 19, 2008 Toshiba announced it would stop
  making HD-DVD players.

• http//politech.files.wordpress.com/2007/02/hd-blu
  ray.JPG

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• http//www.blurayfreak.com/images/2008/02/19/death
  _of_hd_dvd.jpg

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Formatting

• DVD file structure
• Blu-ray file structure

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DVD Format

• Two top level directories AUDIO_TS and VIDEO_TS.
  
• Extra files would be for added features like
  games or web access. These are called hybrid DVDs
• AUDIO_TS isnt used for dvds, was part of the
  original specification
• VIDEO_TS contains VTS (video title set) files for
  each piece of footage

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Visual of DVD file format
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VIDEO_TS

• Menus and navigation are handled in the video_ts
  files
• Usually one VTS will be the main one for the
  movie, with the others representing other
  trailers, special footage, etc.

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.VOB (presentation)

• Contains audio, video, subtitles, and menus.
• File size is capped at 1GB, or it overflows into
  another vob if necessary

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.IFO (navigation)

• Contains navigation instructions for jumps and
  programs, as well as button definitions
• Also houses setup options like language and
  aspect ratio
• Capped at 1GB, and overflows to another IFO if
  necessary

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.BUP (backup)

• These backup files contain copies of the ifo and
  the vob files.
• Intended to be used for recovery from scratches
  on the disk
• They are written near the exterior of the disk,
  away from the original copies.

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Multiplexing

• The term used for mixing multiple streams into
  one file for writing to a disk
• Example MPEG-2. Muxing of an AC3 audio file
  with a subtitle file

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Blu-ray Format

• The top level of a blu-ray disk shows
• BDMV folder PLAYLIST, CLIPINF, STREAM, AUXDATA,
  and BACKUP directories. MovieObject and index
  .bdmv files
• AACS folder DUPLICATE directory, multiple files
  for content security.
• CERTIFICATE BACKUP directory and verification

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BDMV (blu-ray disc movie)

• PLAYLIST playitem files with start/stop times
  for specific clips
• CLIPINF info files for stream files (titles,
  etc)?
• STREAM Audio/Visual stream files
• AUXDATA sound and font datafiles
• BACKUP backups of the other files
• Index.bdmv houses a table for menu info
• MovieObject.bdmv navigation commands for
  executing a playlist

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AACS (advanced access content system)

• MKB_RO.inf, ContentRevocation.lst,
  ContentHash000.cci and others operate together to
  create the blu-ray Advanced Access Content
  System.
• DUPLICATE contains copies of the other AACS
  files.
• Security

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Certificate

• Part of blu-ray standard
• When played, certificate files are checked for
  validity, and against a root-certificate

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Security / Encryption

• Drive to Host authentication
• CSS
• AACS
• BD

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Drive authentication

• All the protocols require a way to encrypt the
  data from the drive to the host
• The drive must verify the host and the host must
  verify drive
• Once they are verified they will setup a session
  key for further communication

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DVD and CSS

• CSS stands for Content Scrambling System
• It is the encryption scheme currently in use on
  DVDs
• It uses a 40bit key
• Each player is licensed a group of keys called
  player keys

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CSS Continued

• There are 4 keys
• Player Key
• Disk Key
• Title Key
• Sector Key

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CSS Decryption

• On each CSS encrypted disk the lead in section
  contains
• A hashed disk key
• 409 disk keys encrypted with corresponding player
  keys
• The player decrypts the corresponding encrypted
  disk key with its player key
• The player will then compare this value against
  the hashed disk key

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CSS Decryption

• Dk Decryption(player key, encrypted Dk)?
• Compare hash(Dk) and hashed_Dk
• Tk Decryption(Dk, encrypted Tk)?
• Sk Decryption(Tk, encrypted Sk)?
• Decryption algorithms use Linear Feedback Shift
  Registers

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CSS Weakness

• Key length is 40 bits or 5 bytes
• Because of reuse (409 player keys) there is
  actually only about 32 bits worth of encryption.
• If one player key is compromised they are all
  possibly compromised.
• DVDs are played on PCs as such at some point in
  time the key is in plaintext in memory.
• Drive to host authentication uses saved secret key

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CSS Cracked

• CSS cracked in 1999.
• DeCSS was one of the first programs to Rip an
  encrypted DVD, Jon Lech Johanson and Masters of
  Reverse Engineering
• Prior to this there were some programs that would
  copy the disk by grabbing the video stream from
  the processor

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DVD key using css-auth
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Blu-Ray and AACS

• Advanced Access Content System
• Key length has been increased to 128 bits
• Uses AES encryption
• AACS Keys
• Device Key
• Processing Key
• Media Key

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AACS Decryption

• Using Device Key search through tree and apply
  AES decryption to get Processing Key
• Using Processing Key apply AES decryption to get
  Media Key
• Compare obtained Media Key to Media verification
  data using AES
• AES_128D(Km, Dv) 0123456789ABCDEF

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AACS ImprovementsOver CSS

• 40 bit key to 128 bit
• Verifying of key happens at the media key level
  not processing key
• AES algorithm for encryption decryption
• Elliptical curve cryptography used for drive to
  host authentication
• Publicly publishing method for review. http//www.
  aacsla.com/specifications/specs091/AACS_Spec_Commo
  n_0.91.pdf

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AACS Cracked
http//hsoj.net/wp-content/uploads/2007/05/aacskey
phtoshop.jpg
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Blu-Ray BD

• Created by Cryptography Research sold to
  Macrovision
• Uses a Java Virtual Machine in the Player that
  can be updated if compromised, BD-J
• Newer titles can be encrypted differently/more
  securely if other are compromised.
• No publicly published standard

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BD Downfalls

• Requires that stand alone players be updated by
  means of creating a CD-R and powering up with it
• Will reset the player settings so that you can
  reconfigure for each update
• Requires internet connection to download firmware
  or order update disc

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BD Cracked Already?

• March 19th 2008 SlySoft claims to have cracked
  the current BD encryption
• Once initially done may be easier for future
  updates

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Regions / Programs

• DVD Regions
• Regional Coding Enhancement
• Blu-Ray Regions
• Player Licenses
• Ripping Software

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DVD Regions

• Why?
• Different release dates
• Price discrimination
• Different content
• How?
• Bit map of one byte on the DVD
• DVD player is responsible for checking the DVDs
  region

http//www.answers.com/topic/dvd-region-code?catt
echnology
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DVD Regions
http//commons.wikimedia.org/wiki/ImageDVD-Region
s_with_key.png
1 U.S., Canada, U.S. Territories 2 Japan,
Europe, South Africa, and Middle East (including
Egypt)? 3 Southeast Asia and East Asia
(including Hong Kong)? 4 Australia, New Zealand,
Pacific Islands, Central America, Mexico, South
America, and the Caribbean 5 Eastern Europe
(Former Soviet Union), Indian subcontinent,
Africa, North Korea, and Mongolia 6 China 7
Reserved 8 Special international venues
(airplanes, cruise ships, etc.)
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Regional Coding Enhancement (RCE)

• DVD contains software to check the DVD players
  region
• Will not play on multi-region players

http//www.dvdtalk.com/rce.html
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Blu-Ray Regions
http//bluray.liesinc.net/index.php?pageinfo
Region A North America, Central America, South
America, Japan, Taiwan, North Korea, South Korea,
Hong Kong and Southeast Asia. Region B Europe,
Greenland, French territories, Middle East,
Africa, Australia and New Zealand. Region C
India, Bangladesh, Nepal, Mainland China,
Pakistan, Russia, Central and South Asia.
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DVD Players

• Licensing fees paid to DVD patent holders to play
  DVDs
• Sony
• Toshiba
• Philips
• AOL Time Warner
• 15 - 20 in licensing fees per DVD player

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DVD Player Software

• Free software exists (VLC Media Player) but may
  not be legal in the United States

With many products the producer pays the
license body (in this case MPEG LA) so the user
(commercial or personal) does not have to take
care of this. VLC cannot do this because they
are Free and Open Source implementations of these
codecs. The software is not sold and therefore
the end-user becomes responsible for complying to
the licensing and royalty requirements. You will
need to contact the licensor on how to comply to
these licenses. This goes for playing a DVD
with VLC for your personal joy (2.50 one time
payment to MPEG LA) as well as for using VLC for
streaming a live event in MPEG-4 over the
Internet. http//www.videolan.org/doc/faq/en/in
dex.htmlid305468
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DVD Ripping Programs

• Five Best DVD Riping Tools compiled from
  lifehacker.com
• DVD Shrink (Windows - Freeware)
• HandBrake (Mac, Linux, Windows - Freeware)
• DVDFab HD Decrypter (Windows - Shareware)
• MacTheRipper (Mac - Freeware)
• DVD Decrypter (Windows - Freeware)?

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http//lifehacker.com/380702/five-best-dvd-ripping
-tools
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Blu-Ray Ripping Programs

• Slysofts AnyDVD HD
• Removes encryption (AACS) from Blu-ray Discs.
• Removes BD copy protection from Blu-ray Discs.
• Removes region codes from Blu-ray Discs.

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http//www.slysoft.com/en/anydvdhd.html
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A Comparison DVD Quality
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A Comparison Highly Compressed DVD
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Questions?
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