Finding counterexamples to ∀∃ hyperproperties

Abstract

Verification of software systems against hyperproperties that require quantifier alternation among the quantified trace variables is notoriously difficult because it generally cannot be reduced to the verification of single-trace properties. Such hyperproperties include the class of ∀∃-safety hyperproperties, which contains important hyperproperties such as refinement and generalized non-interference. Existing approaches to the verification of these properties are often incomplete or restricted to finite-state systems. When the hyperproperty does not hold, no existing approaches can fully automatically produce counterexamples demonstrating this fact. We present an algorithm that searches for counterexamples to ∀∃-safety hyperproperties in infinite-state software systems and evaluate its effectiveness based on existing examples from related works.