Biometrics via Wi-Fi: the new possibilities and their impact on privacy
How Wi-Fi signals are used for identification
Research into biometric identification technologies has developed rapidly in recent years. Whereas cameras or other special sensors were previously required to capture biometric data, systems are now emerging that identify people based on the way they influence wireless networks. This technology exploits the fact that every human body interferes with Wi-Fi signals in a unique way — comparable to an invisible fingerprint.
An Italian research team has developed a novel method that uses channel state information (CSI) to detect minimal changes in Wi-Fi signals and extract individual characteristics of a person. A specially trained neural network evaluates this data by perceiving body shape, size and movement patterns as a unique signature. Almost like science fiction, identification is already achieving an accuracy of more than 95 percent.
AI, deep learning and the ‘invisible fingerprint’
At the heart of this new technology is a multi-layered AI system trained through contrastive learning. This enables artificial intelligence to reliably distinguish between similar and dissimilar patterns. It processes the data points obtained from the Wi-Fi signals and learns to recognise an individual biometric signature for each person.
While classic biometric systems such as facial recognition are highly dependent on external circumstances (lighting conditions, viewing angle, image quality), the analysis of Wi-Fi signals offers major advantages: it works discreetly, independently of visual contact, and can be integrated invisibly into existing networks. This raises the question of how this technology could influence our everyday lives and data protection in the future.
Opportunities and challenges of wireless biometrics
Areas of application and technological advantages
By continuously evaluating channel status information, it is possible to detect even the smallest changes in a room. In addition to identifying individuals, such systems could potentially create movement profiles, detect falls or even analyse gestures, for example for intelligent building control or medical monitoring.
The particular advantage is that for many applications, simply knowing that someone is present or their identity is sufficient, without the need for additional sensors or cameras. This increases efficiency and reduces costs, but also raises completely new questions, particularly in the area of data protection.
Data protection and anonymity: limits of what is possible
With technological progress comes growing concern about privacy. Critics warn that such solutions could usher in a new era of invisible surveillance, in which presence and identity are recorded without the knowledge of the individuals concerned. Even if the raw data from Wi-Fi signals is anonymous, it is only when combined with artificial intelligence that individual characteristics can be decrypted.
The developers emphasise that the original CSI data cannot be used to identify individuals without the associated AI model. However, once such a system is in use, it provides deep insights into people's behaviour and identity – whether in their own homes, at work or in public spaces. Legislators and technology providers have a responsibility to re-evaluate the balance between innovation and privacy.
Conclusion: Innovation between convenience and control
The potential of wireless biometrics and the next steps
The technology for extracting personal data from infrastructure previously considered harmless, such as Wi-Fi, is a milestone in modern IT. The possibilities are endless – from intelligent access control and security systems to the optimisation of smart homes. At the same time, however, there is a growing demand and need to consider data protection and transparency from the outset.
Anyone relying on innovative solutions today should also be aware of the risks and opportunities. Only with clear regulations and responsible handling can advantages such as greater convenience, security and efficiency be made available to everyone.