Transcript Philips Digital and Analog Protection System (Philips DNA) Michael Epstein Raymond Krasinski Martin Rosner October 22-23, 2003

Philips Digital and Analog
Protection System (Philips DNA)
Michael Epstein
Raymond Krasinski
Martin Rosner
October 22-23, 2003
Outline
• Problem Statement
– D-A-D of video content
– Special case: Broadcast content
• Solution Concept
– Two proposals A and B
• Proposal B is the simples subset of proposal A
• Other subsets or combinations are possible
• Tools
– Watermarking
– Zone coding
– Re-conversion detection
• Remote verification
• Summary
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Problem Statement
• D-A-D conversion carriage of content protection states
– Prevent the copying of “copy never” (CN) content
– Prevent improper copying of “one generation” content (COG)
– Prevent the Internet re-transmission to the public (NIR)
• To allow personal use when appropriate
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Features
• Prevents redistribution of video content via the Internet
– Preserves compatibility with legacy equipment
– Permits reasonable transmission of content over the Internet
between appropriate locations
• Provides protection after content is placed on the
Internet without authorization
– Does not fail catastrophically after secured content is
compromised
• Permits manufacture of computers free of any legal
mandate
• Becomes more effective with the passage of time, as the
population of compliant equipment grows
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Solution Concept
• Encryption systems
– Protect content insides a compliant world
– When content is lost to the non-compliant world
• Content is played in the non-compliant world
• Content is played in the compliant world
• DNA system – a holistic solution
– Assume that content will leak to the non-compliant world
– Assume content will want/need to return to the compliant
world
– This will work for all types of content (CN, COG, NIR)
STOP CONTENT FROM RETURNING
TO THE COMPLIANT WORLD
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Assumptions
• It remain difficult to transmit video across the
Internet without using lossey compression
technologies
• It will be desirable to use compliant devices to
record/play/watch video
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Watermark Detection
• Watermark detectors will exist in:
– Optical/magnetic player or recording drives which
will check well known video formats on command
– Video generators
• e.g. computer graphics cards
– Displays
• Televisions or monitors
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Tools
• Watermarks
– Base watermark
– Remark
• Zone coding
– Tagging content with geographic information
• Reconversion detection
– Detect D-A-D
– Detect compression
• Remote verification
– Information at one device aids in decisions of a second
device
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Watermark Fundamentals
• An indelible mark that carries information
– Typically applied by the owner/distributor of content
• Does not interfere with the use of content
• Should be difficult to remove
– Without destroying the content
• Should be difficult to write
• Should be inexpensive to find
– If you know the secrets
• A remark is a watermark that is applied by consumer
equipment according to certain rules
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Zone Coding
• Zone coding for NIR and COG content
– Set at the broadcast station
– Internal Zone code set in devices by inputs
• Quick reset allowed once in a while
• Devices play content that matches the
internally stored zone
– Adjacent zones are also allowed
• Boundary areas
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Zone Coding
NIR-B
NIR content zone B
NIR content zone A
Internet
D/A
NIR-A
DVD Recorder
Unregulated Demodulator
Computer
Display
zone A
zone B
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End Proposal B-Simplified Proposal
• Protects only NIR content
– Prevents retransmission to remote locations
• Most basic proposal using our tools
– Zone coding is a portion of the A proposal
• Combining zone coding with reconversion
detection provides a more complete approach
to NIR content
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Reconversion Detection
• Hash the bits of a “sector” and use the hash to
construct a watermark (or remark) for a
subsequent “sector”
• Verify content against the watermark (or
remark)
– If the content changes verification will fail
• D-A-D conversion inevitably changes content
• So does compression
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Reconversion Detection-Recording
Content
1
2
3
4
5
6
mark
mark
mark
mark
mark
HASH
HASH
HASH
HASH
HASH
1
2
3
4
5
6
Recorded Content
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Reconversion Detection-Checking
mark
equal?
mark
equal?
mark
equal?
mark
equal?
HASH
HASH
HASH
HASH
HASH
1
2
3
4
5
mark
equal?
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Recorded Content
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NIR Example – Hashed Remark
NIR
Television
Receiver
DVD Recorder
NIR – No Internet Retransmission to public
NIR-RM – NIR-remarked
NIR-RM
DVD Player
NIR-RM
DVD Recorder
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Failure to Traverse the Internet
A/D
Internet
DVD Recorder
DVD Player
NIR-Altered content
Non-compliant
DVD Recorder
NIR-RM
(compression)
NIR-RM – NIR-remarked
DVD Player
NIR-Altered content
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Remote Verification
• There will be situations where content is
altered prior to watermark detection for valid
reasons
– e.g. software sharpening
• Content source sends verification data to the
watermark detecting device
– e.g. graphics card works with DVD drive
• Checking device uses source-generated
verification data in conjunction with the
detected watermark
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Remote Verification
Computer
Verification
request
Drive
Video
Generator
Content +
verification data
Display
content
NIR-RM
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Mandates
• All displays must have a watermark detector
• Video generators with uni-directional outputs must
have a watermark detector
– e.g. analog outputs or DVI
• Video generators with bi-directional outputs may
license a watermark detector
• Disk drives (magnetic/optical) may license a watermark
detector
• Thus, a computer that has only bi-directional outputs
need have no watermark detectors at all
– but such a computer will not be able to play marked content
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Summary
• Prevent improper content from coming into the
compliant world
– It is a given that content will leak from the compliant
world to the non-compliant world
• Attach rights to content
– Pervasive protection
• More compliant equipment increases the efficacy
of the solution
– But increases or maintains consumer functionality
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