Modal Logic for Distributed Trust

2026-03-23

AI Summary

This work proposes a modal logic–based framework to address the challenge of formal reasoning about distributed trust relationships in multi-agent systems. By employing nested modal structures, the approach precisely captures the mechanisms of trust propagation along communication chains. It unifies the modeling of agents’ beliefs, communicative actions, and trust assumptions within a single logical framework, and directly compiles these specifications into a computable proof-theoretic λ-calculus. This enables verifiable trust generalization and secure information sharing across networked agents. The resulting formal system not only accommodates canonical distributed trust models such as public-key infrastructures but also provides a composable and formally verifiable foundation for trust reasoning in complex communication scenarios.

Technology Category

• Knowledge Representation and Reasoning: Reasoning with Beliefs
• Multiagent Systems: Agent Communication
• Data Mining & Knowledge Management: Representing, Reasoning, and Using Provenance, Trust

Application Category

• Semantics and Knowledge: Provenance, trust, security and privacy, and ethical issues in managing semantic data
• Security and Privacy: Blockchains and distributed ledgers
• Graph Algorithms and Modeling for the Web: Foundation models and LLMs for Web-related graphs

Abstract

We propose a method for reasoning about trust in multi-agent systems, specifying a language for describing communication protocols and making trust assumptions and derivations. This is given an interpretation in a modal logic for describing the beliefs and communications of agents in a network. We define how information in the network can be shared via forwarding, and how trust between agents can be generalized to trust across networks. We give specifications for the modal logic which can be readily adapted into a lambda calculus of proofs. We show that by nesting modalities, we can describe chains of communication between agents, and establish suitable notions of trust for such chains. We see how this can be applied to trust models in public key infrastructures, as well as other interaction protocols in distributed systems.

Problem

• Modal Logic
• Distributed Trust
• Multi-agent Systems
• Communication Protocols
• Trust Reasoning

Innovation

• modal logic
• distributed trust
• multi-agent systems
• communication protocols
• lambda calculus of proofs