Wi-Fi Biometrics: What Is WhoFi and Why Privacy Experts Are Concerned

Wi-Fi biometrics is emerging as a controversial technology capable of identifying people using nothing more than signal disruptions from existing wireless networks. One of the latest developments in this space is WhoFi, an AI-powered system developed by researchers at La Sapienza University in Rome. Unlike facial recognition or fingerprint scanners, WhoFi relies on Channel State Information (CSI) — subtle variations in Wi-Fi signals — to detect and re-identify individuals. With 95.5% accuracy, WhoFi can track a person through walls or in complete darkness, raising significant privacy concerns. As this non-invasive biometric tool gains attention, many are asking: can our everyday Wi-Fi routers become surveillance devices?

How Wi-Fi Biometrics Work Without Cameras or Physical Contact

At the heart of Wi-Fi biometrics is the way wireless signals interact with the environment. When a person moves through a space, their body distorts Wi-Fi signals in unique patterns. WhoFi uses these changes, captured through CSI, and feeds them into a deep neural network that learns to recognize individual “signal fingerprints.” What makes this particularly powerful is its passive design — no need for wearable sensors, visual data, or consent. The system doesn’t even require line of sight. It quietly reads environmental changes through walls, around furniture, and in low-light conditions, making it a stealthy surveillance tool compared to conventional biometric systems.

Potential Applications of Wi-Fi Biometrics Beyond Surveillance

While privacy advocates raise alarms, researchers are exploring positive use cases for Wi-Fi biometrics. For instance, the same technology could be adapted to monitor elderly people living alone, detect unauthorized access in secure areas, or help smart homes become more responsive to human behavior. Businesses may even leverage it for customer analytics in physical retail stores. WhoFi represents a broader movement in AI research to interpret ambient signals — not just visuals — to understand human activity. However, these benefits must be weighed against the potential for intrusive monitoring without user consent or awareness.

Privacy Implications and the Future of Wi-Fi Biometrics

The introduction of WhoFi has reignited debates around consent and data protection. Unlike traditional biometric systems, Wi-Fi biometrics operates without active user participation, making it harder to regulate or opt out. Governments and regulators may soon need to draft new privacy laws to govern how these invisible identifiers are collected, stored, and used. As AI-driven systems like WhoFi become more accurate and accessible, it’s crucial to ask: who controls the data, and how is it secured? The intersection of AI, wireless technology, and biometrics opens new doors — and new risks — for how human identity is monitored in a hyperconnected world.