Technical Reports (CIS)

Document Type

Technical Report

Date of this Version



University of Pennsylvania Department of Computer and Information Science Technical Report No. MS-CIS-09-10.


Access control and privacy policy relations tend to focus on decision outcomes and are very sensitive to defined terms and state. Small changes or updates to a policy language or vocabulary may make two similar policies incomparable. To address this we develop two flexible policy relations derived from bisimulation in process calculi. Strong licensing compares the outcome of two policies strictly, similar to strong bisimulation. Weak licensing compares the outcome of policies more flexibly by ignoring irrelevant (non-conflicting) differences between outcomes, similar to weak bisimulation. We illustrate the relations using examples from P3P and EPAL.


policy analysis, privacy policies



Date Posted: 17 August 2009