Secure Context-sensitive Authorization


Kazuhiro Minami and David Kotz. Secure Context-sensitive Authorization. Journal of Pervasive and Mobile Computing, volume 1, number 1, pages 123–156. Elsevier, March 2005. doi:10.1016/j.pmcj.2005.01.004. ©Copyright Elsevier. Revision of minami:csa-tr.


There is a recent trend toward rule-based authorization systems to achieve flexible security policies. Also, new sensing technologies in pervasive computing make it possible to define context-sensitive rules, such as “allow database access only to staff who are currently located in the main office.” However, these rules, or the facts that are needed to verify authority, often involve sensitive context information. This paper presents a secure context-sensitive authorization system that protects confidential information in facts or rules. Furthermore, our system allows multiple hosts in a distributed environment to perform the evaluation of an authorization query in a collaborative way; we do not need a universally trusted central host that maintains all the context information. The core of our approach is to decompose a proof for making an authorization decision into a set of sub-proofs produced on multiple different hosts, while preserving the integrity and confidentiality policies of the mutually untrusted principals operating these hosts. We prove the correctness of our algorithm.

Citable with [BibTeX]

Projects: [solar]

Keywords: [context-aware] [security]

Available from the publisher: [DOI]

Available from the author: [bib] [pdf]
This pdf is the authors' near-final copy; the publisher does not allow us to post the final pdf.

[Kotz research]