2024/05/20 by Alfredo Capozucca, Maximiliano Cristiá, Capozucca, Alfredo +5 · 2 citations
Computer Science · #Natural Language Processing Techniques #Multi-Agent Systems and Negotiation
paper · pdf · doi:10.48550/arxiv.2405.12187
This paper revisits the Brewer-Nash security policy model inspired by ethical Chinese Wall policies. We draw attention to the fact that write access can be revoked in the Brewer-Nash model. The semantics of write access were underspecified originally, leading to multiple interpretations for which we provide a modern operational semantics. We go on to modernise the analysis of information flow in the Brewer-Nash model, by adopting a more precise definition adapted from Kessler. For our modernised reformulation, we provide full mechanised coverage for all theorems proposed by Brewer & Nash. Most theorems are established automatically using the tool log with the exception of a theorem regarding information flow, which combines a lemma in log with a theorem mechanised in Coq. Having covered all theorems originally posed by Brewer-Nash, achieving modern precision and mechanisation, we propose this work as a step towards a methodology for automated checking of more complex security policy models.