Centralized vs Decentralized Monitors for Hyperproperties
Abstract
This paper focuses on the runtime verification of hyperproperties expressed in Hyper-recHML, an expressive yet simple logic for describing properties of sets of traces. To this end, we consider a simple language of monitors that observe sets of system executions and report verdicts w.r.t. a given Hyper-recHML formula. We first employ a unique omniscient monitor that centrally observes all system traces. Since centralised monitors are not ideal for distributed settings, we also provide a language for decentralized monitors, where each trace has a dedicated monitor; these monitors yield a unique verdict by communicating their observations to one another. For both the centralized and the decentralized settings, we provide a synthesis procedure that, given a formula, yields a monitor that is correct (i.e., sound and violation complete). A key step in proving the correctness of the synthesis for decentralized monitors is a result showing that, for each formula, the synthesized centralized monitor and its corresponding decentralized one are weakly bisimilar for a suitable notion of weak bisimulation.
Cite
@article{arxiv.2405.12882,
title = {Centralized vs Decentralized Monitors for Hyperproperties},
author = {Luca Aceto and Antonis Achilleos and Elli Anastasiadi and Adrian Francalanza and Daniele Gorla and Jana Wagemaker},
journal= {arXiv preprint arXiv:2405.12882},
year = {2025}
}