Paper 2025/1422

Design ZK-NR: A Post-Quantum Layered Protocol for Legally Explainable Zero-Knowledge Non-Repudiation Attestation

Abstract

This article presents the architectural design of Zero Knowledge Non-Repudiation (ZK-NR), a layered cryptographic protocol enabling post-quantum secure, legally interpretable, and verifiably non-repudiable attestations. Built upon STARK-based zero-knowledge proofs, hybrid post-quantum signatures, and entropy-accumulating ledger anchoring, ZK-NR satisfies the structural properties of both the Q2CSI framework and the NIZK-E model. The protocol achieves semantic interpretability by structurally separating contextual proofs from bounded explanations, while maintaining cryptographic soundness under the Universal Composability framework. Formal UC proofs are deferred to Article A.2 in this series. This article constitutes the first entry in the ZK-NR series, focused specifically on the protocol's architectural and functional design. Subsequent articles will cover its mathematical foundations, implementation strategies, and operational validation using formal verification environments.

Note: This manuscript is part of a structured research program on the legal explainability of post-quantum cryptographic protocols. It presents the architectural design of ZK-NR, a concrete layered protocol instantiating the generic formal framework introduced in “Quantum Composable and Contextual Security Infrastructure (Q2CSI)” (ePrint 2025/1380). This framework itself is based on the theoretical impossibility result known as the CRO Trilemma (ePrint 2025/1348), which establishes a formal incompatibility between confidentiality, reliability, and legal opposability. ZK-NR distributes these three guarantees across semantically orthogonal layers, Iron, Gold, and Clay, and provides a UC-conformant, modular protocol architecture suitable for deployment in adversarial post-quantum environments. While related works may explore its implementation and formal verification, the present manuscript focuses exclusively on the composable protocol design, predicate orthogonality, and semantic layering. This submission is purely theoretical. It does not include any implementation artefacts, benchmarks, or experimental claims. All contributions are original. This manuscript is not under submission or review elsewhere.