Pragmatic XML Access Control Using Off-the-Shelf RDBMS

Abstract

Abstract. As the XML model gets more popular, new needs arise to specify access control within XML model. Various XML access control models and enforcement methods have been proposed recently. However, by and large, these approaches either assume the support of security features from XML databases or use proprietary tools outside of databases. Since there are currently few commercial XML databases with such capabilities, the proposed approaches are not yet practical. Therefore, we explore the problem of "Is is possible to fully support XML access control in RDBMS?" We formalize XML and relational access control models using deep set operators. Then we show that the problem of XML AC atop RDBMS is amount to the problem of converting XML deep set operators into equivalent relational deep set operators. We show the conversion algebra and identify the properties to ensure the correct conversion. Finally, we present three practical implementations of XML access controls using off-the-shelf RDBMS and their performance results.

Relational access control with bivalent permissions in a social Web/collaboration architecture

“…Theoretical work on access control has led to several frameworks for representing access control policies in flexible, fine-grained ways, e.g. [12,17,27]. Rather than assuming a particular policy model, such as DAC, MAC, or RBAC, these frameworks typically provide a way to represent access control rules (ACRs) [22] that may apply to individual users, roles, and groups, as well as to objects, fields, and collections of objects.…”

“…Relational access control (RAC) has been the subject of considerable study in contexts where fine-grained permissions must routinely be assigned, e.g. for XML documents [21,22,26,27]. But to our knowledge the RAC paradigm has not yet been recognized as a significant alternative for collaboration systems.…”

A Rule-Based Relational XML Access Control Model in the Presence of Authorization Conflicts

“…Several researchers have proposed to use the mature relational database technology to store, secure and query XML data [1,5,6,11,12]. Although relational databases support table level and tuple level access control mechanism, they do not provide node-level restriction mechanisms for the hierarchical XML data.…”

Relational Storage for XML Rules

“…There are many algorithms proposed to secure native XML documents, such as [2], [4], [6], [9]. However, there are a few algorithms proposed to apply XML access control technique for XML documents stored in relational databases, such as [10], [11], and [15]. In [10], [11], the XML documents stored in relational database without using XML schema.…”

“…However, there are a few algorithms proposed to apply XML access control technique for XML documents stored in relational databases, such as [10], [11], and [15]. In [10], [11], the XML documents stored in relational database without using XML schema. The proposed technique in [15] used XML schema in storing XML documents in relational database, but it had the following drawbacks [14]:…”