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

Secure Web data/information management l Secure data models - Secure XML, RDF, Relational, object-oriented, text, images, video, etc. l Secure data management functions - Secure query, transactions, storage, metadata l Key components for secure digital libraries and information retrieval/browsing

Secure Web Database Functions

Secure Query Management: Language Issues l 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 l XML extensions for Multimedia databases such as SMIL (Synchronized Multimedia Interface Language) l Mappings between multiple languages l Web rules and query languages developed by W3C l Security should be incorporated into all aspects

Security/Integrity Management l Support for flexible security policies l Negotiations between different database administrators l Authorization and access control models such as role- based access control l Identification and authentication l Privacy Control l Copyright protection / Plagiarism l Maintaining the quality of the data coming from foreign sources l Represent data and policies in XML, RDF, OWL and reason to determine quality and ensure security

Secure Digital Libraries l Digital libraries are e-libraries - Several communities have developed digital libraries l Medical, Social, Library of Congress l Components technologies - Web data management, Multimedia, information retrieval, indexing, browsing, l Security has to be incorporated into all aspects - Secure models for digital libraries, secure functions

Secure Information Retrieval

Secure Browsing l Browser augments a multimedia system to develop a hypermedia system l Search space consist of nodes and links with different access control rules and/or classification levels l May be represented as RDF Graphs l 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 access to heterogeneous databases - both users and application programs; Query, Transaction processing (Relational) (Object- Oriented)

Technical Issues on the Interoperability of Heterogeneous Database Systems l Heterogeneity with respect to data models, schema, query processing, query languages, transaction management, semantics, integrity, and security policies l Federated database management - Collection of cooperating, autonomous, and possibly heterogeneous component database systems, each belonging to one or more federations l Interoperability based on client-server architectures

Federated Database Management Database System A Database System B Database System C Cooperating database systems yet maintaining some degree of autonomy 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 Schema for Component B Generic Schema for Component C Export Schema for Component A Export Schema I for Component B Export Schema for Component C Federated Schema for FDS - 1 Federated Schema for FDS - 2 External Schema 1.2Schema 2.1 External Schema 2.2 External Schema 1.1 Export Schema II for Component B External

Transforming Secure Data Models EMP: Level = Secret SS#EnameSalary D# 1John20K10 2Paul30K20 3Mary40K20 l Class EMP is Secret l It has 3 instances: l John, Paul and Mary DEPT D#DnameMgr 10 Math Smith U 20PhysicsJones C Level l Class DEPT is Unclassified l It has 2 instances Math and Physics l Math is Unclassified l Physics is Confidential

Secure Schema Integration

Security Policy Integration

Federated Data and Policy Management Export Data/Policy Component Data/Policy for Agency A Data/Policy for Federation Export Data/Policy Component Data/Policy for Agency C Component Data/Policy for Agency B Export Data/Policy

Inference Control

Applications of Semantic Web Technologies l Specify generic policies and schema in RDF, OWL l Integrate the generic policies and schemas for federated policies and schemas l Apply reasoning strategies for RDF and OWL for inference control in distributed environments

What are web portals? l 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. l This environment acts as a one-stop shop, or "gateway," for users' information and system needs. l 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. l Enterprise information portals gives large amounts of disparate content and applications unity and continuity. l EIP differs from say a well-developed content managed intranet with respect to “personalization”.

Personalization l 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. l 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. l My Yahoo! and MSN are good examples of Internet portals. l EIPs are developed specifically to work within business environments, often integrating standard corporate collaboration tools , shared calendars, discussion forums, and online meetings into the suite.

Virtual Workspaces l Portals are important for knowledge sharing and virtual workspaces l Firms are increasingly leveraging their globally distributed knowledge resources through deployment of distributed teams. l 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” l 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 l Security and privacy policies determine what information is shared and with whom

Semantic Web Applications for Web Portals l Web portals and Mashups – Web 2.0 and beyond l Utilizes semantic web technologies for information representation and reasoning l RDF and OWL technologies ate being used l Security investigation for web portals and Mashups is relatively new l Need to develop appropriate policies, represent them using semantic web technologies