Minimizing Agents’ State Corruption Resulting from Leak-Free Epistemic Communication Modeling

Abstract

Epistemic Logic (EL) successfully models epistemic and doxastic attitudes of agents and groups in multi-agent systems, including distributed systems, via relational structures called Kripke models. Dynamic Epistemic Logic (DEL) adds communication in the form of model-transforming updates. Private communication is key in distributed systems as processes exchanging (potentially corrupted) information about their private local state may not be detectable by any other process. This focus on privacy clashes with the fact that updates are applied to the whole Kripke model, which is usually commonly known by all agents, potentially leading to information leakage. To avoid information leakage and to minimize the corruption of local states resulting from faulty information, we introduce a special stratified structure for Kripke models using a privatization operation that explicitly breaks the common knowledge of the model. To represent agent-to-agent communication we introduce a novel leakage-free update mechanism for solving the consistent update synthesis task: design an update that makes a given goal formula true while maintaining the consistency of agents’ beliefs, if possible.