Non-Deterministic Planning for Hyperproperty Verification

Raven Beutner, Bernd Finkbeiner

Keywords: hyperproperties, LTL, HyperLTL, temporal logics, nondeterministic planning, verification, information-flow policies, partial observations, game solving

TL;DR: We show that HyperLTL verification can be encoded into non-deterministic planning, yielding an effective verification algorithm that outperforms the SOTA.

Abstract:

Non-deterministic planning aims to find a policy that achieves a given objective in an environment where actions have uncertain effects, and the agent - potentially - only observes parts of the current state.
Hyperproperties are properties that relate multiple paths of a system and can, e.g., capture security and information-flow policies.
Popular logics for expressing hyperproperties - such as HyperLTL - extend LTL by offering selective quantification over executions of a system.
In this paper, we show that planning offers a powerful intermediate language for the automated verification of hyperproperties.
Concretely, we present an algorithm that, given a HyperLTL verification problem, constructs a non-deterministic multi-agent planning instance (in the form of a QDec-POMDP) that, when admitting a plan, implies the satisfaction of the verification problem.
We show that for large fragments of HyperLTL, the resulting planning instance corresponds to a classical, FOND, or POND planning problem.
We implement our encoding in a prototype verification tool and report on encouraging experimental results using off-the-shelf FOND planners.

Category: Short

Student: Graduate

Submission Number: 362