Enabling interoperable and rights-aware DRM using the Semantic Web

Enabling interoperable and rights-aware DRM using the Semantic Web Roberto García [email_address] Universitat de Lleida, Spain September 20, 2007 Sophia Antipolis, France

Where did you say you come from? Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Table of Contents
Introduction
Semantic Web
Objectives
Specification
Conceptualisation
Implementation
Evaluation
Conclusions
Future Work
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Introduction
Digital media: easy production and copy
Digital Rights Management (DRM)
Windows Media DRM, iTunes FairPlay, RealNetworks Helix, Sony MagicGate…
DRM copy play … Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Introduction
Internet: easy distribution
DRM interoperability
REL Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 DRM DRM DRM

Introduction
Need for a standard REL (Rights Expression Language)
Some efforts:
XML-based RELs
Formal syntax XML Schema for standard grammar
Informal semantics Rights Data Dictionaries
Creative Commons simple predefined licenses

XML-based RELs:
Limited expressivity
No interoperability mechanisms
Informal semantics, re-implement for each tool
Creative Commons:
Predefined and closed set of licenses
Non-commercial purposes
Introduction Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Introduction
DRM Watch: “2005 Year in Review: DRM Standards” 1
“… consumer complaints have moved beyond overly restrictive DRMs to lack of interoperability among them…”
“… we see no production implementations …”
“… ContentGuards asserts its patents apply to any REL implementation in DRM…”
Electronic Frontier Foundation 2
“… fail to accommodate… copyright regimes.”
1 http://www.drmwatch.com 2 http://www.eff.org Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Introduction
DRM standardisation difficulties
Internet/Web open and heterogeneous
Copyright complex domain
High level of abstraction (not bits or pixels)
Concentrate on the roots, formalise SEMANTICS
ODRL “ Duplicate ” Reproduction Right Copy MPEG-21 “ Adapt ” CC “ Reproduction ” Copyright Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Introduction
Why semantics are needed?
Common scenario : web search and language ambiguity
Computers get confused because… …though we “see”:
" Smart University " (3rd edition) is an educational program dedicated to advanced technologies of Smart Card, e-ID, . ..
SMART (Sisterhood Mobilized for AIDS/HIV Research and Treatment) was founded in 1998...
SMART University welcomes all women infected or affected by HIV/AIDS who...
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Semantic Web

Introduction
Computers “see”:
 Smart University   

SMART University 

Introduction
XML allows some degree of automation
Data Interface: set of specific tags and grammar ( DTD , XMLSchem a)
< music >
< album format=“ mp3 ”>
< author type=“ group ”>Faithless</ author >
< title >Insomnia</ title >
...
</ album >
</ music >

Introduction
With XML computers “see”:
< music >
< author type=“ group ”>  </ author >
< title >  </ title >
...
</ album >
</ music >

Introduction
Interoperability problem
Global agreement required
Just formal syntax, no semantic interoperability tools
< music >
< author tipo=“ group ”> ...</ author >
< title >...</ title >
...
</ album >
</ music >
< song > < group >...</ group > < title >...</ title > < album >...</ album > <file>...</file> ... </ song > ? Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Semantic Web

Introduction
If the previous tool is presented a piece of data based on a new schema:
< song >
< group >Garbage</ group >
< title >Version 2.0</ title >
< album >Version 2.0</ album >
<file>...</file>
...
</ song >

Introduction
That tool “sees”:
<  >
<  >  </  >
<  >    </  >
<  >    </  >
<  >...</  >
...
</  >
Code interoperability rules case by case

Introduction
Semantic Web proposal
Web + Knowledge Representation
Web wide formal semantics
RDF : semantic net, graph model
RDF Schema : classes, inheritance,…
Web Ontology Language (OWL)
OWL-DL : scalable (decidable and tractable)
Semantic Web Rules

Introduction
RDF provides graph model:
Graph can model:
trees (XML)
tables (DBs)

Introduction
RDFSchema : OOP-like primitives
type
class, property
subclass, subproperty
domain, range
Song Class Audio Class subClassOf http:// music .org / song1 type title Property attribute Property subPropertyOf Literal Class “ ...” title type domain range RDFSchema RDF type Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Semantic Web

Introduction
Web Ontology Language (OWL)
Logic reasoning
Primitives for semantic interoperability
Equivalent classes and properties equivalentClass , equivalentProperty
Disjoint classes disjointWith
Inverse, transitive, symmetric properties inverseOf , TransitiveProperty , SymmetricProperty
Cardinality maxCardinality , minCardinality
Unique value properties FunctionalProperty
Identificative properties InverseFunctionalProperty

Table of Contents
Introduction
Objectives
Specification
Conceptualisation
Implementation
Evaluation
Conclusions
Future Work

Objectives
Semantic Web approach to DRM:
Knowledge Representation tools
Web Wide applicability
Benefits:
Formalise semantics
Facilitate interoperability and implementation
Overcome REL patent ?
Include copyright
Support full value chain

Objectives
Ontology development based on Methontology :
Specification
Conceptualisation (and formalisation)
Implementation
Evaluation
XML Semantics Reuse
Profit from existing XML Schema based RELs
Formalise implicit semantics
XML Schema to Web Ontology
XML data to semantic data (RDF)

Table of Contents
Introduction
Objectives
Specification
Conceptualisation
Implementation
Evaluation
Conclusions
Future Work

Specification
Copyright domain analysis
Generic Ontology
WIPO 1 worldwide harmonisation
Literary, artistic and scientific works (not ideas)
Maybe derived, but always original
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 1 World Intellectual Property Organisation Copyright Treaty, 1996

Specification Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Specification
Applicable to the
“ Controlled P2P metadata diffusion scenario”
Peer A Peer B <rdf:RDF> <rdf:RDF> <rdf:RDF> <rdf:RDF> Make Available Right <rdf:RDF> Reproduction Right Scenario Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Table of Contents
Introduction
Objectives
Specification
Conceptualisation
Creation, Rights and Action Model
Implementation
Evaluation
Conclusions
Future Work

Conceptualisation
Complex domain, build model in three steps:
Creation Model
Rights Model
Action Model

Conceptualisation Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Victor Hugo’s Les Misérables Creation Model

Conceptualisation
Work
“ Mozart's The Magic Flute”. ISWC
Manifestation
“ The printed scores”. ISBN
Performance
“ A scenic play”.
Fixation
“ A sound recording”. ISRC
Communication
“ An Internet stream”.
Instance
“ A CD”. UPC
 has Derivation ┙
 has Manifestation ┙
 has Performance ┙
 ha sFixation ┙
 ha sCommunication ┙
 ha sInstance ┙
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Creation Model

Conceptualisation Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Rights Model

End-users do not hold rights
Usage licenses
Special permissions:
Quotation
Education
Information
Official Act
Private Copy
Parody
Temporary Reproduction
Conceptualisation Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Rights Model

Actions, the building blocks
Conceptualisation Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Action Model

Actions governed by Economic Rights:
Reproduction Right : copy
Distribution Right : distribute; sell, rent, lend
Public Performance Right : perform
Fixation Right : record
Communication Right : communicate; retransmit, broadcast, make available
Transformation Right : transform; adapt, translate

Conceptualisation
End-user actions, to use a…
manifestation: buy
instance: buy
performance: attend
communication: access
broadcast: tune
something made available: access
picture, sculpture
book, CD, DVD
projection, recital, exhibition
TV channel, radio station
web page, stream
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Action Model

Altogether: model copyright value chains
E.g. “serials adapted from literary works”

Actions for users’ special permissions:
Quotation Right : quote , limited extent copy , usually requiring an attribute action
Private Copy Right : copy producing a reproduction for private consumption
Education Right : educational act , any copy , communicate or perform with educational or research purposes
Temporary Reproduction Right : a copy that produces a temporal reproduction
…

Case roles (linguistics): relate actions to involved entities

License building primitives:
Event Patterns : to state what is obliged, permitted or prohibited
Built from actions and case roles
Conceptualisation Scenario All copy events performed by agent “ granted ” who copies “ content01 ” from “ PeerA ” to two peers from the set “ PeerB, PeerC, PeerD ” at any time point six months after “ 2007-06-01 ” Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Action Model

Agree : model permissions
theme points to the permitted event pattern
Conceptualisation Scenario Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Action Model

consequence : model obligations
Points to the obliged event pattern
Conceptualisation Scenario Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Action Model

condition : model a priori conditions
Points to the condition event pattern
Disagree : model prohibitions
theme points to the prohibited event pattern
Other concepts:
Transfer: model interchanges, commercial or not.
Time
Location
...

Rules, examples:
First sale exhaustion: ∀ s:Sell, ∀ i:Instance theme(s,i) -> ¬ ∃ s’:Sell theme(s’,i) ∧ s≠s’
Assign author rights on Manifest:

Table of Contents
Introduction
Objectives
Specification
Conceptualisation
Implementation
Evaluation
Conclusions
Future Work

Implementation
One conceptual model, many implementations
Semantic Web implementation with OWL
OWL-DL variant
enables tractable and decidable reasoning for use-license checking, scalability
Additionally, Semantic Web rules
OWL Full OWL DL OWL Lite + expressivity - complexity Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Implementation
Rights and License Patterns implemented as Classes
Copyright, Reproduction Right, Copy, CopyPattern,...
Uses implemented as Instances
u
if u ∈ Copy Pattern then license pattern authorises u
Reproduction Right Copy Copyright Copy Pattern u ? Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Implementation
License Pattern Class built from constraints on kind of actions, agents, time points, locations, etc.
OWL Building Blocks
Classes for actions (e.g. Copy)
Logical operators (AND, OR, NOT)
OWL Restrictions , constraints on case roles (e.g. agent all values from PublisherSubscribers)

Implementation
Copy pattern restricted to:
digital object ( theme )
group of users ( agent )
or
non-commercial ( aim )
depending on
time range ( pointInTime )
Scenario Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Implementation
Description Logic notation for the commercial copy pattern:
Pattern ≡ Copy ⊓ ∀ pointInTime .≥ 2007-01-01,≤ 2007-06-30 ⊓ ∀ agen t.PublisherSubscribers ⊓ (≥ 1 agent ) ⊓ ∃ theme .{urn:doi.10.1032/…} ⊓ (≤ 1 theme )

Implementation
Patterns permitted by Agree actions and prohibited by Disagree ones.
Algorithm:
If disagreed  not allowed
If agreed and not disagreed  allowed
If not agreed  not allowed
Disagree precedence allows:
Revocation
More complex patterns
Avoid DL reasoners limitations (details Annex A)

Implementation Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Copy all copy actions Pattern 2 Pattern 2’ Allowed Pattern 1 Agree Disagree Agree

Implementation
OWL-DL reasoners services:
Satisfiability : consistency, license verification
Subsumption : compute subclasses
License interactions
License search
Instance Checking : class an individual belongs to
Check uses against licenses
Other:
Debugging , justifications for conclusions
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 Pattern A Pattern B Pattern Use

Implementation
OWL-DL limitations:
No explicit variables
Difficult to model rules (if … then …)
Semantic Web rules
Variables
Classical rules
Built-ins (math, comparisons, date/time ops,...)
Integrates OWL

Table of Contents
Introduction
Objectives
Specification
Conceptualisation
Implementation
Evaluation
Conclusions
Future Work

Evaluation
Map MPEG-21 and ODRL ontologies to Copyright Ontology
Based on XML Semantics Reuse Methodology
XML Schemas  OWL Ontologies
XML instances  RDF metadata
MPEG-21, ISO/IEC 21000
Part 5 – REL, XML Schemas:
Core  RELOnto-R
Standard Extensions  RELOnto-SX
Multimedia Extensions  RELOnto-MX
Part 6 – RDD, informal ontology  RDDOnto

Evaluation
ODRL 1.1 (OMA V1.0 DRM REL)
XML Schemas:
Expression Language  ODRLOnto-EX
Data Dictionary  ODRLOnto-DD
Benefits
Check Copyright Ontology coverage
Apply semantic tools existing RELs
Validate MPEG-21 RDD standard
Implement Data Dictionary inheritance
License checking
…

Evaluation
Build SemDRMS Semantic Digital Rights Management System
Controlled P2P metadata diffusion
Peer A SemDRM copy make available Licenses Store DL Reasoner Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Evaluation
Digital Media Project (DMP)
Traditional Rights and Usages informal descriptions, difficult to incorporate into DRM systems
Quote
Private Copy
Time Shift
...
Copyright Ontology: profit from copyright model and capture rights exceptions
No enforcing mechanisms, accountability

Evaluation
Quote scenario
Right exception model:

Evaluation
Concrete quote action:
Tim wants to quote 10 seconds of a work by John

Evaluation
Checking:
Result:

Evaluation
Private Copy scenario
Right exception model:

Evaluation
Concrete private copy action:
Peter wants to produce a personal copy of “My best quote of the year”

Evaluation
Checking:
Result

Table of Contents
Introduction
Objectives
Specification
Conceptualisation
Implementation
Evaluation
Conclusions
Future Work

Conclusions
Concentrate on semantics
Ontology , more expressivity
Include copyright
Facilitate implementation and interoperability
Reuse DL reasoners for license checking
RELs ontologies, XML Semantics Reuse

Table of Contents
Introduction
Objectives
Specification
Conceptualisation
Implementation
Evaluation
Conclusions
Future Work

Future Work
Full SemDRMS based on OWL-DL Copyright Ontology
Complete Mappings to Copyright Ontology
MPEG-21 REL Ontologies
ODRL Ontologies
Creative Commons
Security and trust through RDF signatures

More details: http://rhizomik.net/ontologies/copyrightonto http://rhizomik.net/semdrms http://rhizomik.net/~roberto/thesis Smart University DRM, from research to implementations Thank you for your attention Roberto García [email_address] Universitat de Lleida, Spain

Smart University DRM, from research to implementations Annex A Implementation Details How to deal with licenses using Description Logic reasoners

Implementation
Pattern ⊑ Copy
Pattern ≡ ∀ pointInTime.≥ 2006-01-01, ≤ 2006-06-30 ⊓ ∃ agent.{granted} ⊓ ∃ origin.{peerA} ⊓ ∃ theme.{fragment01} ⊓ (≤ 2 recipient) ⊓ ∀ recipient.{peerB, peerC, peerD}
Scenario Agree Problem Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Implementation
Problem : Open World Assumption (OWA)
OWA sensible constructs:
m ax Cardinality (≤ n): new facts can make cardinality ≥ n
allValuesFrom ( ∀ R.C): new facts where R.(¬C)
…
OWA insensible constructs:
m in Cardinality (≥ n): once ≥ n, new facts cannot make cardinality ≤ n
someValuesFrom ( ∃ R.C): once R.C, new facts cannot make ¬( ∃ R.C)
…
0 1 3 2 maxCardinality 2 (n ≤ 2) minCardinality 3 (n ≥ 3) New facts “ OPEN WORLD” Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Implementation
Metalevel negation to overcome OWA
Agree OWA insensible constructs
∃ , ≥,…
Disagree “negated” OWL sensible constructs
∀ R.C  ∃ R.¬C
≤ n  ≥ n+1
Allowed(u)  Agree.theme(u) ⊓ ¬Disagree.theme(u)

Implementation
Pattern’ ⊑ Copy
Pattern’ ≡ ∀ pointInTime.≥ 2006-01-01, ≤ 2006-06-30 ⊓ ∃ agent.{granted} ⊓ ∃ origin.{peerA} ⊓ ∃ theme.{fragment0001}
Pattern’’ ≡ Pattern’ ⊓ ( ( ≥ 3 recipient) ⊔ ∃ recipient.( ¬ {peerC, peerD, peerB}) )
Scenario Agree Disagree Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Implementation Scenario [ a Copy; agent :granted; origin :peerA; theme :fragment02 ; recipient :peerB ] [ a Copy; agent :granted; origin :peerA; theme :fragment01; recipient :peerC, :peerD ] [ a Copy; agent :granted; origin :peerA; theme :fragment01; recipient :peerB , :peerC, :peer E ] Allowed Copy Pattern ’ Pattern’’ Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007

Enabling interoperable and rights-aware DRM using the Semantic Web

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Enabling interoperable and rights-aware DRM using the Semantic Web — Presentation Transcript