Supporting XML Security Models Using Relational Databases: A Vision

Abstract

Abstract. As the secure distribution and sharing of information over the World Wide Web becomes increasingly important, the needs for flexible and efficient support of access control systems naturally arise. Since the eXtensible Markup Language (XML) is emerging as the format of the Internet era for storing and exchanging information, there have been, recently, many proposals to extend the XML model to incorporate security aspects. To the lesser or greater extent, however, such proposals neglect the fact that the data for XML documents will most likely reside in relational databases, and consequently do not utilize various security models proposed for and implemented in relational databases. In this paper, we take a rather different approach. We explore how to support security models for XML documents by leveraging on techniques developed for relational databases. More specifically, in our approach, (1) Users make XML queries against the given XML view/schema, (2) Access controls for XML data are also specified in the XML model, but (3) Data are stored in relational databases, and (4) Security check and query evaluation are also done in relational databases. Instead of re-inventing wheels, we take two representative methods in both XML security model and XML to relational conversion problems, and show how to glue them together in a seamless manner to efficiently support access controls for the XML model using relational databases.

A Security Model Based on Relational Model for Semantic Sensor Networks

“…v i is created to control access to partial data in the base table according to the defined security policy. As a result, access types of users could be classified into four classes as follows [21]. The access types are same with granularity types.…”

Observation-Based Fine Grained Access Control for XML Documents

“…Various proposals in support of fine-grained XML access control have been introduced in the literature. These include View-based [2,8,9], Non-Deterministic Finite Automata (NFA)-based [4,21,22], RDBMS-based [18,19,27] XML Access Control Enforcement Techniques, etc. The idea of view-based access control is to create and maintain separate view for each user based on the authorization rules.…”

“…Although, Relational Database Management System, due to its structured nature, becomes inappropriate in the context of World Wide Web, most data for XML documents still reside in relational databases behind the scene. The proposals in [18,27,19] takes advantage of relational model, by mapping all the XML data and access controls rules for XML data (in XML format) into the equivalent relational database and structured query language representation. Finally, the accessibility of the data are checked at the level of relational database representation using the SQL representation of the rules.…”

SS-RBAC: Secure Query Processing Model for Semantic Sensor Networks

“…As a result, access types of users could be classified into four classes as follows [21]: Class-I: whole data in a table (Table level) Class-II: all data in specific fields (Column level) Class-III: all data in specific tuples (Row level) Class-IV: random data (Cell level)…”