Building Trustworthy Semantic Webs

Dr. Bhavani Thuraisingham

The University of Texas at Dallas

Semantic web technologies for secure interoperability and digital libraries

November 10, 2008

Outline

Secure Digital libraries and semantic web Secure heterogeneous/federated data management and

semantic web Secure web portals

Secure Web data/information management

Secure data models

- Secure XML, RDF, - - - -

- Relational, object-oriented, text, images, video, etc. Secure data management functions

- Secure query, transactions, storage, metadata Key components for secure digital libraries and

information retrieval/browsing

Secure Web Database Functions

Secure Web Data

Management

Secure Metadata Management Secure Data Warehousing Secure Web Mining

Secure Interoperability

Secure Query Processing Secure Transaction ManagementSecure Storage Management

Security and Integrity

Secure Query Management: Language Issues

Query language to access the databases

- SQL extensions are being examined

- XML-based query languages combined with SQL are emerging

- Example: XML-QL

- Querying RDF Data XML extensions for Multimedia databases such as SMIL

(Synchronized Multimedia Interface Language)

Mappings between multiple languages

Web rules and query languages developed by W3C

Security should be incorporated into all aspects

Security/Integrity Management

Support for flexible security policies

Negotiations between different database administrators

Authorization and access control models such as role-based access control

Identification and authentication Privacy Control Copyright protection / Plagiarism Maintaining the quality of the data coming from foreign

sources Represent data and policies in XML, RDF, OWL and

reason to determine quality and ensure security

Secure Digital Libraries

Digital libraries are e-libraries

- Several communities have developed digital libraries Medical, Social, Library of Congress

Components technologies

- Web data management, Multimedia, information retrieval, indexing, browsing, -- - -

Security has to be incorporated into all aspects

- Secure models for digital libraries, secure functions

Secure Information Retrieval

Secure QueryProcessor

Secure Browser/Editor

Secure UpdateProcessor

Security/IntegrityManager

Secure Metadata Manager

Secure StorageManager

Secure StorageManager

Secure Browsing

Browser augments a multimedia system to develop a hypermedia system

Search space consist of nodes and links with different access control rules and/or classification levels

May be represented as RDF Graphs Can a user traverse a link or access the contents of a node?

- What authorization does he/she have?

Interoperability of Heterogeneous Database Systems

Database System A Database System B

Network

Database System C(Legacy)

Transparent accessto heterogeneousdatabases - both usersand application programs;Query, Transactionprocessing

(Relational) (Object-Oriented)

Technical Issues on the Interoperability of Heterogeneous Database Systems

Heterogeneity with respect to data models, schema, query processing, query languages, transaction management, semantics, integrity, and security policies

Federated database management

- Collection of cooperating, autonomous, and possibly heterogeneous component database systems, each belonging to one or more federations

Interoperability based on client-server architectures

Federated Database Management

Database System A Database System B

Database System C

Cooperating databasesystems yet maintainingsome degree ofautonomy

Federation F1

Federation F2

Schema Integration and Transformation in a Federated Environment

Adapted from Sheth and Larson, ACM Computing Surveys, September 1990

Component Schema for Component A

Component Schema for Component B

Component Schema for Component C

Generic Schema for Component A

Generic Schemafor Component B

Generic Schemafor Component C

Export Schemafor Component A

Export Schema Ifor Component B

Export Schemafor Component C

Federated Schemafor FDS - 1

Federated Schemafor FDS - 2

ExternalSchema 1.2 Schema 2.1

ExternalSchema 2.2

ExternalSchema 1.1

Export Schema IIfor Component B

External

Transforming Secure Data Models

EMP: Level = Secret

SS# Ename Salary D#

1 John 20K 10

2 Paul 30K 20

3 Mary 40K 20

Class EMP is SecretIt has 3 instances:

John, Paul and Mary

DEPT

D# Dname Mgr

10 Math Smith U

20 Physics Jones C

Level

Class DEPT is UnclassifiedIt has 2 instances Math and Physics

Math is UnclassifiedPhysics is Confidential

Secure Schema Integration

Secure Schemas at the Componentlevel: e.g., Component schemasfor components A, B, and C

Generic schemas for the components:e.g., generic schemas for components A, B, and C

External schemas: Schemasfor the various classes of users

Layer 1

Layer 2

Layer 5

Federated schemas: integrate export schemas of the components of the federation

Layer 4

Export schemas for the components:e.g., export schemas for components A, B, and C(note: component may export different schemasto different federations)

Layer 3

Security must be maintained during transformations

Security Policy Integration

Policies at the Componentlevel: e.g., Component policiesfor components A, B, and C

Generic policies for the components:e.g., generic policies for components A, B, and C

Export policies for the components:e.g., export policies for components A, B, and C(note: component may export different policiesto different federations)

Federated policies: integrate export policies of the components of the federation

External policies: Policiesfor the various classes of users

Layer 1

Layer 2

Layer 3

Layer 4

Layer 5

Federated Data and Policy Management

ExportData/Policy

ComponentData/Policy for

Agency A

Data/Policy for Federation

ExportData/Policy

ComponentData/Policy for

Agency C

ComponentData/Policy for

Agency B

ExportData/Policy

Inference Control

ExportEngine

Component Data System for Agency A

Federated Data Management

ExportEngine

ComponentData SystemFor Agency C

ComponentData Systemfor Agency B

ExportEngine

Federated Inference Controller

Inference Controller

Inference Controller

Inference Controller

ExportEngine

Component Data System for Agency A

Federated Data Management

ExportEngine

ComponentData SystemFor Agency C

ComponentData Systemfor Agency B

ExportEngine

Federated Inference Controller

Inference Controller

Inference Controller

Inference Controller

ExportEngine

Component Data System for Agency A

Federated Data Management

ExportEngine

ComponentData SystemFor Agency C

ComponentData Systemfor Agency B

ExportEngine

Federated Inference Controller

Inference Controller

Inference Controller

Inference Controller

ExportEngine

Component Data System for Agency A

Federated Data Management

ExportEngine

ComponentData SystemFor Agency C

ComponentData Systemfor Agency B

ExportEngine

Federated Inference Controller

Inference Controller

Inference Controller

Inference Controller

Applications of Semantic Web Technologies

Specify generic policies and schema in RDF, OWL Integrate the generic policies and schemas for federated

policies and schemas Apply reasoning strategies for RDF and OWL for inference

control in distributed environments

What are web portals?

A portal, or enterprise information portal (EIP), is a Web site that integrates an organization's knowledge base and all related applications into a single user-customizable environment.

This environment acts as a one-stop shop, or "gateway," for users' information and system needs.

An organization's entire content database; search facilities; collaboration tools; individual department, workgroup, and project-specific intranets; online applications; and security mechanisms fused into one cohesive environment that's accessible from a single starting point.

Enterprise information portals gives large amounts of disparate content and applications unity and continuity.

EIP differs from say a well-developed content managed intranet with respect to “personalization”.

Personalization EIP differs from say a well-developed content managed

intranet with respect to “personalization”. EIPs allow users to customize their portal environment to deliver only the content they're interested in.

This means every user who logs onto the portal will have a different view of the system and its content. For example, a Human Resources Manager will not need to see revisions of some engineering drawing but would like to receive news on the latest salary compensation trends.

My Yahoo! and MSN are good examples of Internet portals. EIPs are developed specifically to work within business

environments, often integrating standard corporate collaboration tools e-mail, shared calendars, discussion forums, and online meetings into the suite .

Virtual Workspaces Portals are important for knowledge sharing and virtual

workspaces Firms are increasingly leveraging their globally distributed

knowledge resources through deployment of distributed teams. Since face-to-face meetings are increasingly less common among

distributed teams, team members are more frequently sharing their knowledge through the use of “virtual workspaces”

Virtual workspaces are an integrated set of tools that offer a variety of communication support capabilities including a common team repository organized for easy search and retrieval, application sharing, electronic whiteboards and group discussion forums

Security and privacy policies determine what information is shared and with whom

Semantic Web Applications for Web Portals

Web portals and Mashups – Web 2.0 and beyond Utilizes semantic web technologies for information

representation and reasoning RDF and OWL technologies ate being used Security investigation for web portals and Mashups is

relatively new Need to develop appropriate policies, represent them using

semantic web technologies