Complexity guarantees for explicit propagation and locally mixed solvers

Establish general complexity guarantees for explicit issuer-propagation optimization and for strategies that combine different propagation models or solvers across local graph regions.

Background

The paper separates its core arborescence-based credential-propagation model from explicit issuer-reachability analysis for shared-issuer deployments. The implementation currently applies one propagation model to an entire instance and does not combine different models or solvers across distinct graph regions. The authors leave unresolved both the complexity theory of the explicit-propagation formulation and the guarantees available for locally mixed solution strategies.

References

General guarantees for explicit propagation and such locally mixed strategies remain open.

— Optimizing Credential Blast Radius Through Trust Boundaries and Delegation Under Post-Quantum Authentication Costs  (2609.04566 - Taipale et al., 3 Sep 2026) in Section 5, subsection “Guarantees and limits”

General complexity guarantees and globally coordinated mixtures of core and explicit-propagation scoring remain open.

— Optimizing Credential Blast Radius Through Trust Boundaries and Delegation Under Post-Quantum Authentication Costs  (2609.04566 - Taipale et al., 3 Sep 2026) in Section 6, “Limitations”

Its gate is sample- and channel-conditioned but spatially shared to preserve one DCT/IDCT path, so efficient location-dependent routing remains open.

— TailProp: content-adaptive light- and heavy-tailed propagation for vision  (2609.11081 - Kong et al., 10 Sep 2026) in Section 6, Limitations and Future Work