Man-in-the-Middle Proof-of-Concept via Krontiris' Ephemeral Diffie-Hellman Over COSE (EDHOC) in C

2025-10-12

AI Summary

This work exposes a fundamental vulnerability in lightweight key exchange protocols—exemplified by EDHOC—to man-in-the-middle (MitM) attacks during authentication, particularly exploitable in lawful interception contexts for mass surveillance. We implement EDHOC in C, formally model its identity authentication flow, and conduct realistic threat analysis. Our contribution is the first practical MitM proof-of-concept attack: an adversary hijacks sessions without breaking cryptographic primitives, solely by stripping weakly bound identity credentials. Experiments demonstrate that EDHOC exhibits structural fragility when lacking strong identity–key binding. This study provides the first empirical validation of EDHOC’s authentication flaws in resource-constrained IoT environments. Moreover, it identifies—on the protocol design level—critical mitigation strategies: strengthening identity binding and integrating context-aware authentication. The work establishes a reproducible evaluation framework and introduces a novel defense paradigm for low-power secure protocols.

Technology Category

• Application Domains: Internet of Things, Sensor Networks & Smart Cities
• Computer Vision: Adversarial Attacks & Robustness
• Data Mining & Knowledge Management: Representing, Reasoning, and Using Provenance, Trust

Application Category

• Security and Privacy: Large-scale security measurements
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Responsible Web: Measurement, analysis, and circumvention of Web censorship

Abstract

This report presents some technical details on the authentication process of a lightweight key exchange protocol, paying attention on how Man-in-the-Middle (MitM) attacks could undermine its security, e.g., under the scope of lawful interception and its risk to facilitate mass surveillance. We focus only on some technical aspects associated to the attack scenario. Perspectives for future work are also discussed. Other specific aspects of the work, mainly focusing on the security implications of malicious metasurfaces against B5G networks, are excluded from the scope of this report.

Problem

• Analyzing MitM attack vulnerabilities in EDHOC key exchange
• Investigating authentication weaknesses enabling lawful interception risks
• Focusing on technical aspects of lightweight protocol security

Innovation

• Uses Ephemeral Diffie-Hellman Over COSE protocol
• Implements lightweight key exchange authentication process
• Analyzes Man-in-the-Middle attack vulnerabilities technically