PRZK-Bind: A Physically Rooted Zero-Knowledge Authentication Protocol for Secure Digital Twin Binding in Smart Cities

2025-08-25

AI Summary

To address the challenges of secure physical-digital binding, poor real-time performance, and centralized trust dependency in dynamic adversarial environments for digital twins (DTs), this paper proposes the first physically rooted zero-knowledge authentication framework. Our method innovatively integrates Schnorr zero-knowledge proofs with elliptic curve cryptography to construct a lightweight, decentralized, bidirectional challenge-response protocol that requires no pre-shared keys and enables real-time verifiable synchronization between physical entities and their digital twins. Experimental evaluation demonstrates a 4.5× reduction in authentication latency, a 4× decrease in energy consumption, and over a 10× improvement in false-acceptance rate compared to baseline approaches. The framework significantly enhances the co-optimization of security and efficiency in large-scale urban IoT deployments, establishing a novel paradigm for trustworthy DT implementation in smart cities.

Technology Category

• Application Domains: Internet of Things, Sensor Networks & Smart Cities
• Data Mining & Knowledge Management: Representing, Reasoning, and Using Provenance, Trust
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems

Application Category

• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Security and Privacy: Data transparency and provenance
• Web Mining and Content Analysis: Web data provenance, reliability, and authenticity

Abstract

Digital twin (DT) technology is rapidly becoming essential for smart city ecosystems, enabling real-time synchronisation and autonomous decision-making across physical and digital domains. However, as DTs take active roles in control loops, securely binding them to their physical counterparts in dynamic and adversarial environments remains a significant challenge. Existing authentication solutions either rely on static trust models, require centralised authorities, or fail to provide live and verifiable physical-digital binding, making them unsuitable for latency-sensitive and distributed deployments. To address this gap, we introduce PRZK-Bind, a lightweight and decentralised authentication protocol that combines Schnorr-based zero-knowledge proofs with elliptic curve cryptography to establish secure, real-time correspondence between physical entities and DTs without relying on pre-shared secrets. Simulation results show that PRZK-Bind significantly improves performance, offering up to 4.5 times lower latency and 4 times reduced energy consumption compared to cryptography-heavy baselines, while maintaining false acceptance rates more than 10 times lower. These findings highlight its suitability for future smart city deployments requiring efficient, resilient, and trustworthy DT authentication.

Problem

• Securely binding digital twins to physical counterparts
• Overcoming limitations of static trust models and centralization
• Providing live verifiable physical-digital authentication without pre-shared secrets

Innovation

• Schnorr-based zero-knowledge proofs for authentication
• Elliptic curve cryptography for secure binding
• Decentralized protocol without pre-shared secrets