Privacy-Preserving Secure Neighbor Discovery for Wireless Networks

2025-03-28

AI Summary

In Secure Neighbor Discovery (SND), device identity and location privacy are highly vulnerable—especially in IoT deployments—where conventional SND protocols require disclosure of real identifiers and geographic coordinates for distance bounding and direct communication authentication, thereby introducing significant privacy risks and hindering practical adoption. Method: This paper proposes PP-SND, a privacy-preserving SND protocol that uniquely integrates homomorphic encryption with pseudonymous authentication. It decouples core SND functionalities—authentication, integrity, and distance verification—from identity and location exposure, achieving pseudonymity, confidentiality, and unlinkability. Physical-layer time-of-flight–based ranging ensures robustness against wormhole attacks. Results: Experimental evaluation on Raspberry Pi 4 demonstrates that PP-SND preserves essential SND security properties while substantially mitigating privacy leakage. Moreover, it exhibits cross-technology generality, supporting diverse wireless communication standards.

Technology Category

• Application Domains: Internet of Things, Sensor Networks & Smart Cities
• Machine Learning: Privacy
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems

Application Category

• Security and Privacy: Privacy-enhancing technologies
• Systems and Infrastructure for Web, Mobile and WoT: Location- and context-aware Web and WoT applications and services
• User Modeling, Personalization and Recommendation: User privacy protection in personalized systems

Abstract

Traditional Neighbor Discovery (ND) and Secure Neighbor Discovery (SND) are key elements for network functionality. SND is a hard problem, satisfying not only typical security properties (authentication, integrity) but also verification of direct communication, which involves distance estimation based on time measurements and device coordinates. Defeating relay attacks, also known as"wormholes", leading to stealthy Byzantine links and significant degradation of communication and adversarial control, is key in many wireless networked systems. However, SND is not concerned with privacy; it necessitates revealing the identity and location of the device(s) participating in the protocol execution. This can be a deterrent for deployment, especially involving user-held devices in the emerging Internet of Things (IoT) enabled smart environments. To address this challenge, we present a novel Privacy-Preserving Secure Neighbor Discovery (PP-SND) protocol, enabling devices to perform SND without revealing their actual identities and locations, effectively decoupling discovery from the exposure of sensitive information. We use Homomorphic Encryption (HE) for computing device distances without revealing their actual coordinates, as well as employing a pseudonymous device authentication to hide identities while preserving communication integrity. PP-SND provides SND [1] along with pseudonymity, confidentiality, and unlinkability. Our presentation here is not specific to one wireless technology, and we assess the performance of the protocols (cryptographic overhead) on a Raspberry Pi 4 and provide a security and privacy analysis.

Problem

• Ensures secure neighbor discovery without revealing identities
• Prevents relay attacks in wireless network systems
• Protects device location privacy using homomorphic encryption

Innovation

• Homomorphic Encryption for distance computation
• Pseudonymous device authentication for identity hiding
• Decoupling discovery from sensitive information exposure