pqRPKI: A Practical RPKI Architecture for the Post-Quantum Era

TL;DR

pqRPKI introduces a practical post-quantum RPKI architecture using Merkle trees and ladder-guided sync, significantly reducing repository size and validation time while supporting dual-stack deployment with current trust anchors.

Contribution

It presents pqRPKI, a novel post-quantum RPKI framework that redesigns validation workflows and data structures for efficiency and compatibility with existing infrastructure.

Findings

Reduces repository footprint by up to 83.1% compared to Falcon.

Cuts full-cycle validation time to approximately 103 seconds.

Enables sub-2-minute validation cycles with minimal size overhead.

Abstract

The Resource Public Key Infrastructure (RPKI) secures Internet routing by binding IP prefixes to authorized Autonomous Systems, yet its RSA foundations are vulnerable to quantum adversaries. A naive swap to post-quantum (PQ) signatures (eg Falcon) is a poor fit for RPKI's bulk model: every relying party (RP) repeatedly fetches and validates the entire global repository, so larger keys and signatures inflate bandwidth and CPU cost, especially during a long dual-stack transition. We present pqRPKI , a post-quantum RPKI framework that pairs a multi-layer Merkle Tree Ladder (MTL) with RPKI objects, customized to relocate per-object verification material from certificates into the Manifest. To update RPKI for Merkle tree based schemes, pqRPKI redesign the RPKI manifest and delegation chain, introduces a ladder-guided sync and bulk-verification workflow that lets validators localize diffs top-down and rebuild trees bottom-up. pqRPKI also preserves current RPKI objects and encodings, supports both hosted and delegated operation, and provides an additive migration path that coexists with today's trust anchors for dual-stack deployment with little size overhead. Implemented as a working publication point (PP) and RPs, we show that pqRPKI reduces repository footprint to 546.8 MB on average (65.5%/83.1% smaller than Falcon/ML-DSA), cuts full-cycle validation to 102.7 s, and achieves 118.3 s end-to-end PP to Router time, enabling sub-2-minute operating cadences with full-repository validation each cycle. Dual-stack deployment with RSA only adds just 3.4% size overhead versus today's RPKI repositories.