MIT CSAIL

Policy Assurance in Database Systems

Overview

This directory houses the files for Jose Soltren's M. Eng. thesis, "Query-Based Database Policy Assurance Using Semantic Web Technologies". Some slides giving an overview are available here. This work is closely related to the IARPA-PIR project, which describes many of the scenarios herein. This page has a narrower focus than the IARPA-PIR page; for further details, please refer to the thesis.

SPARQL to N3 Translator

The SPARQL to N3 translator is now live. It accepts a SPARQL query as input, and gives its translation to N3. The ontology for the translation is also available.

Automatic Policy Generation

We now support automated policy generation using policy templates from the thesis. The supported policies are: restriction, inclusion, exclusion, chaining, and default deny. The requirements for each policy are different, so please visit the policy generator page for further details. The policy generator outputs an AIR policy in N3, which is viewable in Tabulator and usable as is. (In Firefox, please type Ctrl+U to see page source and access the policy itself if necessary.)

Policy Execution Page

The Policy Execution Page accepts the URI of a policy and the URI of a SPARQL query in N3 as input. It passes these along to the AIR reasoner, and displays the reasoning output in a Web browser. If you have Tabulator installed, the results will appear nicely in the Justification UI.

Justification User Interface

As explanations are usually in the form of proof trees, which might be incomprehensible to end users, DIG has developed a graphical Justification User Interface in Tabulator, a Firefox extension for Semantic Web browsing. The interface allows users to view the explanation provided by the AIR reasoner in different ways: (i) in a simple Semantic Web based rule language, and (ii) in a graphical layout that highlights the result of the reasoning and shows both its natural language explanation as well as its specific premises (or dependencies) and allows these explanations to be explored. This project is compatible with the Justification UI.

Download Tabulator Firefox extension to view all demos.

Test Cases

A list of test cases is now available. This list offers some simple demo policies that demonstrate the core functionality of policy generation, query conversion, and reasoner output.

Use Cases

The IARPA-PIR project defines a number of use cases; check there for further details. The use cases provide excellent examples of some of the ideas mentioned in the thesis in practice.
  • Use Case 0, the first demo scenario with examples by Lalana Kagal.
  • Use Case 1, which introduced template policies and common usage patterns.
  • Use Case 2, which moved to a new, simpler translation and introduced USE and RETRIEVE, as well as the idea of a mandatory include.
  • Use Case 3, the first to specify a query history.

References


Valid XHTML 1.0!
maintained by Jose Hiram Soltren
 $Rev: 29172 $
$Date: 2010-05-27 13:09:46 -0400 (Thu, 27 May 2010) $