Unique Biometric Tools: Wi-Fi Knows Where You Are and Who You Are

The wireless networking technology Wi-Fi no longer only provides internet access but also enables covert tracking. If you are within its range, it knows at any moment – where you are and who you are. The secret companion is a new tool of Wi-Fi technology – called WhoFi – which recognizes people by the way their body disrupts the Wi-Fi signal, developed by scientists at La Sapienza University in Rome. Wi-Fi transmits data wirelessly using radio waves, allowing computers, mobile phones, and similar devices to connect to the internet and exchange information.

However, through this technology, multiple devices can connect even without an internet connection, for example, in offices. WhoFi is a new biometric tool for recognizing individuals, more powerful than fingerprint recognition systems, a method over a century old created by Argentine Croat Juan Vucetich Kovacevich, and iris recognition, and it is not fixed like cameras and scanners but can track a person wherever there is Wi-Fi coverage.

Hot Discovery

The authors of the study and computer scientists Danilo Avola, Daniele Pannone, Dario Montagnini, and Emad Emam presented WhoFi as a new biometric identifier. WhoFi does not rely on visual elements, wearable devices, or behavioral signs but provides a unique signature of a person created from information about the state of the Wi-Fi channel that records changes in amplitude and phase of the signal as electromagnetic waves pass through physical obstacles.

– The fundamental insight is that as the Wi-Fi signal spreads through the environment, the presence of objects and people in its path alters its waveform. The WhoFi implementation records information about the channel state and describes in detail how the Wi-Fi signal changes as it moves through space and around people, then converts those changes into a compact biometric signature unique to the person it encounters. These changes contain valuable biometric information – the scientists announced.

They trained a deep neural network to recognize signal changes unique to each person. The system thus learns to differentiate people by analyzing how each person affects the Wi-Fi signal, even in different environments. Using a deep learning model, WhoFi achieved a re-identification accuracy of up to 95.5 percent.

Older and New Insights

The study involved fourteen participants who moved under various conditions, and the results achieved by WhoFi were evaluated on the NTU-Fi Human ID. The NTU-Fi Human ID dataset includes measurements recorded by CSI (channel state information), which analyzes the features of the Wi-Fi signal and reveals changes in the environment and human activities such as walking, breathing, chewing… However, recognizing people using Wi-Fi is not new; scientists have researched this multiple times over the last decade. Ten years ago, scientists from MIT (Massachusetts Institute of Technology) demonstrated that low-bandwidth Wi-Fi can track people through walls as frequencies spread through obstacles.

Five years ago, EyeFi, a system combining Wi-Fi with a camera, showed about 75 percent accuracy in identifying people during live testing in groups of two to ten individuals. However, WhoFi is much more advanced as it does not use a camera and learns directly from CSI data. By eliminating cameras, it avoids capturing faces and reduces sensitivity to clothing, utilizing existing infrastructure in homes and offices.

WhoFi is insensitive to lighting, can operate even when a person is out of sight by transmitting frequency signal data about them while standing or walking between transmitters and receivers, the amplitudes and phases on those layers shift according to the person’s movement, and it uses an encoder to create a fixed-length vector representing that person. The data is then compared to see if there is a close neighbor of the same person… The biggest limitation in the research of the Italian scientists related to diversity as the fourteen participants did not encompass a range of all body types.

– Wi-Fi signals offer several advantages over camera-based approaches: they are not affected by lighting, can penetrate walls and other obstacles, and most importantly, they offer privacy preservation – stated Avola, who led the research at the Roman university.

Growth Triggers

Although the new biometric tool WhoFi is currently just the result of one study and still far from commercialization, it is likely to pique the curiosity of investors as the biometric identification market is growing rapidly. By 2025, according to a MarketsandMarkets report, the value of the global biometric identification market is estimated to be around $53.2 billion. Some other sources claim differently, but estimates range from $52 billion to $68.6 billion, depending on the research methodology. If the biometric market reaches $52 billion this year, it will signify a growth of 16.5 percent compared to last year when it was valued at $45.18 billion. The significant growth of this market is driven by security issues, government initiatives, rising cyber threats, increasing integration into smart devices, and growing acceptance of usage.

Accordingly, the biometric market is projected to be worth $93.57 billion by 2029, with an annual growth rate of 15.5 percent, which can be attributed to the emergence of biometrics as a service (BaaS), expansion in healthcare, border control and immigration, and in financial services. Key trends in the forecast period include the integration of artificial intelligence and machine learning, rapid technological advancement, the expansion of mobile biometrics, and an emphasis on privacy and data regulation.

Authentication and Identification

The driver of growth in the biometric market is also the increasing acceptance of biometric technology in consumer electronics for authentication and identification applications. Biometric sensors are present in smartphones and other devices, and consumer electronic devices: door locks, security systems, home automation, IoT devices, cars, gaming consoles, and mobile devices are increasingly applying biometric technology to enhance security features. While fingerprint, facial, and voice recognition methods are gaining importance as preferred means of authentication for access and payments. According to a Visa study conducted three years ago, 86 percent of consumers expressed interest in using biometrics for identity verification during payments, 70 percent of consumers found biometrics easier to use, and 46 percent considered it more secure than passwords or PINs. This means that in the foreseeable future, the increasing integration of biometric technology into consumer electronics for authentication and identification applications will drive the growth of the biometric market. This is also influenced by artificial intelligence (AI), which is transforming the fingerprint biometric market by improving the speed and accuracy of recognition systems.

AI-driven algorithms enable real-time fingerprint matching, even with partial prints or damaged skin. Deep learning models enhance the system’s resistance to fraud, strengthening trust in biometric security, and integration with machine vision and multimodal biometrics, which is used to support standard verification procedures, expands the scope of application where fingerprints are analyzed alongside facial or iris recognition for greater accuracy.

Privacy Threat

However, when it comes to the WhoFi tool, critics argue that persistent tracking, especially when it occurs without the knowledge or consent of the subjects, could open the door to new forms of covert surveillance. The Italian researchers acknowledge that their innovation could threaten privacy and are aware of the potential misuse if this biometric tool is applied one day without legal restrictions, but they assert that WhoFi does not directly record the identity or personal data of individuals. Furthermore, the commercialization of WhoFi is not currently anticipated, nor has the state shown interest. However, the problem is that people are consciously and unconsciously constantly under the influence of Wi-Fi signals, and if the discovery of this research were to soon become just another commercialized new technology, invisible tracking could become routine and threaten both security and privacy. The application of WhoFi would be inexpensive, allowing tracking without permission. For example, stores could use this technology to track customers without seeking permission.

Assistance in Adversity

Nevertheless, there is also a positive side to using the new tool; for instance, in hospitals, it could be used to detect patient falls in a room. In industrial facilities where cameras are prohibited, WhoFi could be used to monitor unauthorized entry and activate alarms. Regardless, it is no longer in question whether this new technology will overpower humanity, but rather how quickly it will happen. Who knows what wilderness technological curiosity will one day lead civilization into? Modern technology already mentally and intellectually cripples humanity, making it lazy and unrealistically complacent. Thanks to technology, many believe that everything is easy and accessible with little effort, like clicking on the screen of an electronic device, and as such, they become easy technological ‘prey’.