Philips Digital and Analog Protection System (Philips

DNA)

Michael EpsteinRaymond KrasinskiMartin RosnerOctober 22-23, 2003

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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

InternetInternet

D/A

NIR-ADVD Recorder

zone Azone B

NIR-B

NIR content zone B

NIR content zone A

DisplayComputer

Unregulated Demodulator

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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

1 2

HASH

Content

Recorded Content

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HASH

4

HASH

5

HASH

6

HASH

21 3 4 5 6

mark mark mark mark mark

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Reconversion Detection-Checking

HASH

markequal?

Recorded Content

HASH HASH HASH HASH

21 3 4 5 6

markequal?

markequal?

markequal?

markequal?

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NIR Example – Hashed Remark

NIR

DVD Recorder NIR-RM

DVD Player

DVD Recorder

TelevisionReceiver

NIR – No Internet Retransmission to public

NIR-RM – NIR-remarked NIR-RM

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Failure to Traverse the Internet

NIR-RM

InternetInternet

NIR-Altered content

DVD Recorder

DVD Player

A/D

(compression)

Non-compliant DVD Recorder

DVD PlayerNIR-Altered content

NIR-RM – NIR-remarked

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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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Drive DisplayVideo

Generator

Computer

content

NIR-RM

Content +verification data

Verificationrequest

Remote Verification

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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