enabling interoperable and rights-aware drm using the semantic web
DESCRIPTION
This presentation, which was carried out at the DRM track of SmartUniversity'07, presents a Semantic Web approach to Digital Rights Management. This approach is based on a Copyright Ontology, implemented using OWL and DL reasoning.TRANSCRIPT
Enabling interoperable and rights-aware DRM using the Semantic Web
Roberto Garcí[email protected]
Universitat de Lleida, Spain
September 20, 2007Sophia Antipolis, France
Smart University DRM, from research to implementations
Where did you say you come from?
2Enabling 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 3
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 4
Introduction
• Internet: easy distribution• DRM interoperability
DRM
DRM
DRM
REL
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 5
Introduction
• Need for a standard REL (Rights Expression Language)
• Some efforts:– XML-based RELs
• Formal syntaxXML Schema for standard grammar
• Informal semanticsRights Data Dictionaries
– Creative Commons simple predefined licenses
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 6
• 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
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 7
Introduction
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 8
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 9
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 10
Semantic Web
Introduction
• Computers “see”:
Smart University
SMART University
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 11
Semantic Web
Introduction
• XML allows some degree of automation– Data Interface: set of specific tags and
grammar (DTD, XMLSchema)
<music> <album format=“mp3”> <author
type=“group”>Faithless</author> <title>Insomnia</title> ... </album></music>
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 12
Semantic Web
Introduction
• With XML computers “see”:
<music> <album format=“mp3”> <author type=“group”></author> <title></title> ... </album></music>
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 13
Semantic Web
Introduction
• Interoperability problem• Global agreement required
– Just formal syntax, no semantic interoperability tools
<music> <album format=“mp3”> <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 14
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>
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 15
Semantic Web
Introduction
• That tool “sees”:
<> <></> <></> <></> <>...</> ...</>
• Code interoperability rules case by case
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 16
Semantic Web
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
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 17
Semantic Web
Album
Listcontains
Song "..."
"..."title
item_1 title
item_2Song "..."title
MusicGroupauthor
author
release
Introduction
• RDF provides graph model:
• Graph can model:– trees (XML)– tables (DBs)
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 18
Semantic Web
SongClass
AudioClass
subClassOf
http://music.org/song1
type
titleProperty
attributeProperty
subPropertyOf
LiteralClass
“...”
title
type
domain
range
RDFS
chem
aR
DF
type
Introduction
• RDFSchema: OOP-like primitives– type– class, property– subclass, subproperty– domain, range
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 19
Semantic Web
Introduction
• Web Ontology Language (OWL)– Logic reasoning– Primitives for semantic interoperability
• Equivalent classes and propertiesequivalentClass, equivalentProperty
• Disjoint classesdisjointWith
• Inverse, transitive, symmetric propertiesinverseOf, TransitiveProperty, SymmetricProperty
• CardinalitymaxCardinality, minCardinality
• Unique value propertiesFunctionalProperty
• Identificative properties InverseFunctionalProperty
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 20
Semantic Web
Table of Contents
• Introduction• Objectives• Specification• Conceptualisation• Implementation• Evaluation• Conclusions• Future Work
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 21
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
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 22
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)
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 23
Table of Contents
• Introduction• Objectives• Specification• Conceptualisation• Implementation• Evaluation• Conclusions• Future Work
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 24
Specification
• Copyright domain analysis• Generic Ontology
– WIPO1 worldwide harmonisation
• Literary, artistic and scientific works (not ideas)• Maybe derived, but always original
Intellectual Property Rights
Author Rights or WIPO Copyright
Industrial Property
Economic Rights or Exploitation Rights or
CopyrightMoral Rights
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
1 World Intellectual Property Organisation Copyright Treaty, 1996
25
Specification
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
Exploitation Right (Copyright)
Reproduction Right
Fixation RightSound Recording RightMotion Picture Right
Communication RightBroadcast RightPublic Performance Right
Distribution RightRental Right
Transformation RightAdaptation RightTranslation Right
MoralRight
Dissemination RightPaternity RightRespect RightWithdrawal Right
Neighbouring RightsPerformers, Producers, Broadcasters Rights
Sui Generis Right
Rights Exceptions
Private CopyQuotationEducation...
Intellectual Property Rights
26
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 27
Table of Contents
• Introduction• Objectives• Specification• Conceptualisation
– Creation, Rights and Action Model
• Implementation• Evaluation• Conclusions• Future Work
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 28
Conceptualisation
• Complex domain, build model in three steps:
Creation Model
Rights Model
Action Model
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 29
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 30
Conceptualisation
Fixation
Instance
Manifestation
Work
Performance
Objects Processes
Communication
AbstractionsVictor 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
hasDerivation┙
hasManifestation┙
hasPerformance┙
hasFixation┙
hasCommunication┙
hasInstance┙
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 31
Creation Model
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 32
Conceptualisation
Copyright
EconomicRights
RelatedRights
MoralRights
DistributionRight
ReproductionRight
PublicPerformanceRight
FixationRight
CommunicationRight
AttributionRight
TransformationRight
IntegrityRight
DisclosureRight
WithdrawalRight
PermorfersRights
ProducersRights
BroadcastersRights
RentalRight
ImportationRight
SoundRecordRight
MotionPictureRight
BroadcastingRight
MakingAvailableRight
AdaptationRight
TranslationRight
Rights Model
• End-users do not hold rights– Usage licenses– Special permissions:
• Quotation• Education• Information• Official Act• Private Copy• Parody• Temporary Reproduction
33Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
ConceptualisationRights Model
• Actions, the building blocks
Fixation
Instance
Manifestation
Work
Performance
manifest
perform
improvise
fix
reproduce
reproduce
Objects Processes
Communicationcommunicate
Abstractions
transform
distribute retransmit
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 34
ConceptualisationAction 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
35Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
ConceptualisationAction Model
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 36
Action Model
• Altogether: model copyright value chains – E.g. “serials adapted from literary works”
37Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
ConceptualisationAction Model
Creator Actor Producer Broadcaster User
Motion PictureScript
Adaptation Performance
manifest perform record
Communication
broadcastadapt
Literary Work
tune
• 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
– …
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 38
Action ModelConceptualisation
• Case roles (linguistics): relate actions to involved entities
initiator resource goal essence
Action agent, instrument result, patient,effector recipient theme
Process agent, matter result, patient,origin recipient theme
Transfer agent, instrument, experiencer, themeorigin medium recipient
Spatial origin path destination location
Temporal start duration completion pointInTime
Ambient reason manner aim, conditionconsequence
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 39
Action ModelConceptualisation
• License building primitives:– Event Patterns:
to state what is obliged, permitted or prohibited• Built from actions and case roles
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 40
Action ModelConceptualisation
• License building primitives:– Agree: model permissions
• theme points to the permitted event pattern
Scenario
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 41
Action ModelConceptualisation
• License building primitives:– consequence: model obligations
• Points to the obliged event pattern
Copy
theme
content01theme
Transfer
consequence
granted agent
recipient
start
3 €
P6M duration
theme
agent recipient
2007-06-01T00:00+01
peerBpeerCpeerD
peerAorigin
grantergranted
0..2
Scenario
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 42
Action ModelConceptualisation
• License building primitives:– 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• ...
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 43
Action ModelConceptualisation
• Rules, examples:– First sale exhaustion:
∀s:Sell,∀i:Instance theme(s,i)→¬∃s’:Sell theme(s’,i)∧s≠s’
– Assign author rights on Manifest:
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
Manifest
Workurn:iswc:T-034.524.680-1
theme
urn:x500:CN=U07831,O=Composers,C=ES
agent
2007-04-10T09:30:10Z
Manifestationurn:ismn:M-2306-7118-7
resultpointInTime
eslocation
Workurn:iswc:T-034.524.680-1
essenceurn:x500:CN=U07831,O=Composers,C=ES
agent
2007-04-10T09:30:10Z
MoralRights
start
essence
EconomicRights
Manifestationurn:ismn:M-2306-7118-7
agent
start
isManifestationOf
eslocation location
44
Action ModelConceptualisation
Table of Contents
• Introduction• Objectives• Specification• Conceptualisation• Implementation• Evaluation• Conclusions• Future Work
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 45
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 46
Implementation
• Rights and License Patterns implemented as Classes– Copyright, Reproduction Right,
Copy, CopyPattern,...
• Uses implemented as Instances– u
• if u ∈ Copy Pattern thenlicense pattern authorises u
Reproduction Right
Copy
Copyright
CopyPattern
u
?
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 47
Implementation
• License Pattern Classbuilt 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)
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 48
Copy
pointInTime [2007/01/01-2007/06/30]
agent = Publisher Subscribers
them
e =
doi:1
0.10
32/..
.
aim = Non-Commercial
copy theme doi:10.1032/…
pointInTime ≥2007/07/01
licensed actions
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 49
Implementation
• Description Logic notation for the commercial copy pattern:
Pattern ≡ Copy ⊓
∀pointInTime.≥ 2007-01-01,≤ 2007-06-30 ⊓ ∀agent.PublisherSubscribers ⊓ (≥ 1 agent) ⊓
∃theme.{urn:doi.10.1032/…} ⊓ (≤ 1 theme)
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 50
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)
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 51
Implementation
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
Copyall copy actions
Pattern 2
Pattern 2’
Allowed
Pattern 1
Agree
DisagreeAgree
52
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
53
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
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 54
Table of Contents
• Introduction• Objectives• Specification• Conceptualisation• Implementation• Evaluation• Conclusions• Future Work
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 55
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
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 56
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• …
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 57
Evaluation
• Build SemDRMSSemantic Digital Rights Management System– Controlled P2P metadata diffusion
Peer A
SemDRM copy
make available
Licenses Store
DLReasoner
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 58
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
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 59
Evaluation
• Quote scenario– Right exception model:
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
Agree
Quote Manifestationagent
consequence
Person agent
Person theme
theme
Attribute Personexperiencer
WorkisManifestationOf
Person
author
?x?y
60
Evaluation
• Concrete quote action:– Tim wants to quote 10 seconds of a work by
John
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
a Quote
http://tim.org/quotes…
agent
P10s duration
Tim doi:10.1032/...theme
result isPartOf
iswc:T-3452...
isManifestationOf
Johnauthor
61
Evaluation
• Checking:
• Result:
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
Copy
Quote ⊓ ∀ agent.Person ⊓ ( ≥ 1 agent) ⊓
∀ theme.Manifestation ⊓ ( ≥ 1 theme)
[ a Quote;agent :Tim;theme <urn:doi:10.1032/…>;result <http://tim.org/quotes…> ]
a Quoteagent
agent
Tim
doi:10.1032/...theme
John
consequence
Attribute experiencer
iswc:T-3452...
isManifestationOf
author
62
Evaluation
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
• Private Copy scenario– Right exception model:
Agree
Copy
agent
aim
Person
theme
theme
private
result
Instance
Agree
Use
agent
theme
theme
Instance
Person?x isDirectlyRelatedTo
?y
63
Evaluation
• Concrete private copy action:– Peter wants to produce a personal copy of “My
best quote of the year”
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
a Copy
http://peter.org/copies…
agentPeter doi:10.1032/...theme
result
aim
private
64
Copy
Copy ⊓ ∃agent.Person ∃⊓ theme.Instance ⊓
∃result.Instance ⊓ ∃Aim.{private}
[ a Copy;agent :Peter;theme <urn:doi:10.1032/…>;result <http://peter.org/copies…>;aim <private> ]
Evaluation
• Checking:
• Result
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007
a Copy
http://peter.org/copies…
agentPeter result
Agree
Useagent
theme
themePerson
isDirectlyRelatedTo
65
Table of Contents
• Introduction• Objectives• Specification• Conceptualisation• Implementation• Evaluation• Conclusions• Future Work
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 66
Conclusions
• Concentrate on semantics• Ontology, more expressivity• Include copyright• Facilitate implementation and
interoperability– Reuse DL reasoners for license checking– RELs ontologies, XML Semantics Reuse
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 67
Table of Contents
• Introduction• Objectives• Specification• Conceptualisation• Implementation• Evaluation• Conclusions• Future Work
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 68
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
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 69
More details:http://rhizomik.net/ontologies/copyrightonto http://rhizomik.net/semdrms http://rhizomik.net/~roberto/thesis
Smart UniversityDRM, from research to implementations
Thank you for your attention
Roberto Garcí[email protected]
Universitat de Lleida, Spain
Smart UniversityDRM, from research to implementations
Annex A
Implementation DetailsHow 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 72
Implementation
• Problem: Open World Assumption (OWA)• OWA sensible constructs:
– maxCardinality (≤ n): new facts can make cardinality ≥ n
– allValuesFrom (∀R.C): new facts where R.(¬C)– …
• OWA insensible constructs:– minCardinality (≥ n): once ≥ n, new facts cannot
make cardinality ≤ n– someValuesFrom (∃R.C): once R.C, new facts
cannot make ¬(∃R.C)– …
0 1 32
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 73
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)
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 74
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
Disagre
e
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 75
ImplementationScenario
[ 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, :peerE ]
Allowed
Copy
Pattern’
Pattern’’
Enabling interoperable and rights-aware DRM using the Semantic Web – © Roberto García 2007 76