Wi-Fi Trace Anonymization with K-Anonymity Control in Trusted Execution Environments

• Pedro V. Rubinstein UFRJ
• Fernando Dias de M. Silva UFRJ
• Guilherme A. Thomaz UFRJ
• Miguel Elias M. Campista UFRJ
• Luís Henrique M. K. Costa UFRJ

DOI: https://doi.org/10.5753/sbrc.2026.20005

Abstract

Wi-Fi monitoring leverages several applications, such as localization and counting people. Yet, preserving user privacy remains a critical concern. At the same time, data collection devices operating in public and unsupervised environments are vulnerable to attacks which may compromise them. This work presents a Wi-Fi sniffer that leverages trusted execution environments during the sniffing process to securely anonymize data on the device. As a result, the anonymity of previously stored data is preserved even in the presence of attackers with full control over the device’s operating system. To this end, the proposed sniffer enforces a k-anonymity level for MAC addresses. Furthermore, the implementation optimizes memory usage to only 10 MB of RAM considered the traditional and trusted execution environments, enabling deployment on resource constrained devices. Experimental results show that the latency added by cryptographic routines within the trusted environment does not prevent Wi-Fi monitoring in realistic scenarios.

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