access control for linked data: past, present and future

Access Control for Linked Data: Past, Present and Future

Sabrina Kirrane

Insight Centre for Data Analytics, NUIG

Department of Maths and Computing, GMIT

Structure of the Talk

<title> Hello World </title>

She’ll know what to do

with <title>

Ah yes, I display

this at the top.

From document markup (HTML) …

To data markup (XML)…

<time=“10:36”/>

She’ll know what <time>

means

This is what my user

asked for. Thanks!

To arbitrary information exchange ???

<sabrina lecturesAt GMIT/>

This is the data I have. What’s a

sabrina?

<Sabrina lecturesAt GMIT/>

To Semantics…

Publishing and Consuming Linked Data

RDB2RDF

RDB2RDF

RDB2RDFInterface

1.1

Why do we need Access Control?

Access Control and RDF – The Past


Models

Mandatory Access Control

Models

TOP SECRET

SECRET

CONFIDENTIAL

PUBLIC

Access Labels

SubjectsResources

Yagüe et al, Applying the semantic web to access control, 2003Kodali et al, An authorization model for multimedia digital libraries,

2004

Discretionary Access Control

DELETE

UPDATE

CREATE

READ

Delegate

Permissions

SubjectsResources

Gabillon and Letouzey, A view based access control model for sparql, 2010

Models

Role Based Access Control

DELETE

UPDATE

CREATE

READ

SalesMarketi

ng

Roles

Permissions

Employee

SubjectsResources

Finin et al, Rowlbac: Representing role based access control in owl, 2008

Models

Attribute Based Access Control

Age > 21

Affiliation =

Insight

DELETE

UPDATE

CREATE

READ

Attributes

Permissions

SubjectsResources

Priebe et al, A pattern system for access control, 2004

Models

Context Based Access Control

Device=

mobileNear

= Insight

Attributes

DELETE

UPDATE

CREATE

READ

Permissions

SubjectsResources

Luca Costabello et al, Linked data access goes mobile: Context-aware authorization for graph stores, 2012

Models


Models

eXtensible Access Control Markup Language

Policy Administration Point (PAP))Policy Enforcement Point (PEP)Policy Decision Point (PDP)Policy Information Point (PIP)

Ferrini and Bertino, Supporting rbac with xacml+owl, 2009

https://www.oasis-open.org/committees/tc_home.php?wg_abbrev=xacml

Web Access Control

Serena Villata et al, An access control model for linked data, 2011Sacco and Passant, A privacy preference ontology (ppo) for linked data,

2011

1. Give read access to the WebID profile document /2013/card to everyone.

2. Gives read access to the /2013/protected resource, to the members of a group that went to a particular conference.

http://www.w3.org/wiki/WebAccessControl

http://www.w3.org/2005/Incubator/webid/spec/

WebID Profile

Platform for Privacy Preferences

Garcia and Toledo, A web service privacy framework based on a policy approach enhanced with ontologies, 2008

http://www.w3.org/TR/P3P/


Models

Ontology Based Enforcement - KAoS

actors (human and agents)

actionse.g. accessing, communication and monitoringauthorisations and obligationspositive and negative

entities associated with actions

Bradshaw et al, KAoS: Toward an Industrial-strength Open Agent Architecture, 1997

Policy Administration Tool

GuardsEnforcer

s

Domain Manager

s


Policy Admin ToolUser friendly interface for those that are not familiar with DAML and OWLDomain ManagersManage membership and distribute policies to GuardsGuardsEnforce platform independent policiesEnforcersEnforce platform dependent policies (Interface for developers)


Policy Administration Tool

GuardsEnforcer

s

Domain Manager

s


Policies can easily be merged / adopted by others

Deductive Reasoninginfer new policies based on relationship between access control entities

Abductive reasoningdetermine the access rights required to meet a given policy


Rule Based Enforcement - Rei

users and agents

speech actsdelegation, revocation, request,cancel, promise and commanddeontic logicpermissions, prohibitions, obligations and dispensations

services and resources

Kagal and Finin, A policy language for a pervasive computing environment, 2003

Rule Based Enforcement - Rei

Client Mode Server Mode

The server:1. retrieves the relevant

policies 2. requests the credentials

necessary to access the resource from the client

3. verifies the client credentials against the policies

1. The server returns a link to a policy which the client must satisfy

2. The client generates a proof that the requester can satisfy the policy

3. The client forwards the proof to the server.

Kagal and Finin, A policy language for a pervasive computing environment, 2003

Rule Based Enforcement - Protune

users and agents

Decision predicatesoutcome of the policyProvisional predicatesconditions- credentials and declarationsAbbreviation predicatesAbstractions used for simplification

services and resources

Bonatti et al, Protune: A rule-based provisional trust negotiation framework


inference engine

execution

handler

negotiation handler

Framework


Negotiation handlersending conditions and processing responses

Execution handlerinteract with external systems and data sources

Inference Engine enforcing policies (deduction) and retrieving evidences (abduction)


• How-to queries (provide a description of the policy)• What-if queries (give foresight into potential policy outcomes)• Why queries (give explanations for positive negotiations outcomes)• Why-not queries (give explanations for negative outcomes)

Explanations

inference engine

execution

handler

negotiation handler

Framework


Combining Description Logic And Rules

Like KAoS ontologies to model both domain

information and policies - conflict

resolution and harmonisation at design

time

Like Reirules used to support dynamic

constraints and run time variables -

access control based on dynamic

context pertaining o the requester or

the environment

Like Protune policy disclosure and policy negotiation

Toninelli et al, Rule-based and ontology-based

policies

Kolovski et al, Analyzing web access control policies

Use defeasible description logic

Strict Rules that cannot be

overwritten

Defeasible rules that may be

overwritten by a higher priority rule

to understand the effect and the consequence of sets of XACML access control policiesToninelli et al, Rule-based and ontology-based policies: Toward a hybrid

approach, 2005Kolovski et al, Analyzing web access control policies, 2007


Models

Specification – Patterns, Views & Ontologies

entx:EmployeeData {entx:JB rdf:type foaf:Person .entx:JB foaf:givenName "Joe".…}

?X rdf:type foaf:Person ?G Construct & Describe Queries

Reddivari et al, Policy-based access

control for an rdf store., 2005

Gabillon and Letouzey, A view based access

control model for sparql, 2010

Sacco and Passant, A privacy preference

ontology (ppo) for linked data, 2011

Reasoning – Based on ontology concepts

entx:EmployeeData {entx:JB rdf:type entx:Employee .entx:JB foaf:givenName "Joe".entx:JB foaf:lastName "Bloggs". entx:JB entx:salary “40000". entx:MR rdf:type entx:Employee .entx:MR foaf:givenName “May“ .entx:MR foaf:lastName “Ryan".entx:MR entx:salary “80000".entx:Employee rdfs:subClassOf foaf:Person.}

?X rdf:type foaf:Person .

Class -> SubClass

Property -> SubProperty

Class->Instances

Qin et al, Concept-level access control for the semantic web, 2003Javanmardi et al, Sbac: A semantic based access control model, 2006

Partial Query Results

Query Rewriting

Data Filtering

Dietzold and Auer, Access control on rdf triple stores from a semantic wiki perspective, 2006.

Abel et al, Enabling advanced and context dependent access control in rdf stores, 2007

Access Control and Linked Data – The Present

August 2014

Access Control and Linked Data

Models


Data

ContextPolicy

Luca Costabello et al, Access control for http operations on linked data, 2013


Data

FOAF ProfilePolicy

Sacco and Passant, A privacy preference manager for the social semantic web, 2011

RDB2RDF

RDB2RDF

Kirrane et al, Linked Data with Access Control, 2015

Linked Data Authorisation Architecture

Linked Data Authorisation Architecture

RDB2RDF

RDB2RDF

Kirrane et al, Linked Data with Access Control, 2015.

Access Control and Linked Data – The Future

Yagüe et al. Access control and the layers of the Semantic Web

Damiani et al. Weitzner et al. Paradigms where privacy is a key requirement

De Coi et al. Bonatti and Olmedilla Interplay between trust, access control and policy languages

Ryutov et et Access should be based on the Graph structure

Access Control for Linked Data – The Future

Access Control for Linked Data – The Future

SpecificationGranularityUnderlying FormalismReasoningCondition ExpressivenessAttributes, Context & EvidencesHeterogeneity & Interoperability

ImplementationDelegationConsistency & SafetyUsabilityUnderstandability

AdministrationEffectivenessDistributedFlexibility & Extensibility

EnforcementNegotiationExplanationsConflict Resolution

access control for linked data: past, present and future

Technology