Existence of alternative techniques for IFO verification beyond the studied approaches

Identify verification techniques for initial-and-final-state opacity that are not based on trellis/semigroup construction or language-inclusion observer methods, and determine their computational complexity.

Background

The paper analyzes complexity and provides benchmarks for two textbook approaches (trellis-based semigroup construction and classical inclusion-based verification), and a general inclusion-based scheme (Algorithm 3). It establishes tight super-exponential complexity for the textbook methods.

Beyond assessing Algorithm 3’s tightness, the authors explicitly highlight the need to explore fundamentally different techniques for verifying IFO, suggesting potential avenues for improved complexity or practical performance.