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You unlock your phone with your face, your fingerprint sends your laptop whirring into action, you pass airport security by glancing at a camera. Biometric technology has become so woven into the daily routine that for many people, it barely registers any more.

That invisibility is part of the point. These systems are usually fast, convenient and feel secure. Unlike a , you can’t forget your face. But that doesn’t mean they are without risk.

Biometrics fall into two broad families:  (fingerprints, faces, irises, even nailbed patterns) and  (how you walk or type, the rhythm of your speech, the angle you hold your phone).

Both forms are already being widely used – you just may not realise it. Many banks and retailers now  – from swipes, taps and scrolls to the angle you hold your phone, the rhythm of how you move between fields, and the pressure of your touch. If someone else picks up your unlocked phone and tries to access your banking app, this can automatically trigger a fraud alert.

My  even shows it’s possible to infer a user’s name and native language from the timing patterns of their keystrokes.

The graphic below shows the full extent of biometric technologies. Those marked dark green are in widespread commercial and government use today – including less-familiar examples such as the  and other bodily .

Physiological and behavioural biometric systems:

Biometric technology colour-coded by use status, from active to still in research. Image courtesy of Professor Oli Buckley.

 – reading how you walk – is already used for security and surveillance purposes, from venue access to detecting potentially suspicious behaviour. You can wear a mask, pull up a hood, avoid looking at a camera – but you can’t easily change how you walk.

China’s authorities have been  for nearly a decade. And in 2023, the UK’s Biometrics and Forensic Ethics Group . This is usually a sign that operational use isn’t far behind.

A number of other biometric technologies (marked light green), ranging from skin texture and ear shape to micro-expressions and hand-grip patterns, are being actively researched for use in the near future. A further group (marked red) have so far only been demonstrated in the laboratory. But even body odour and breath signatures are further along than their novelty might suggest.

What once felt like science fiction is now embedded in our everyday lives. You can’t always see this technology, and you can’t always opt out. But knowing it exists is the first step to understanding how much of yourself you’re already sharing.

V is for vulnerability

In April 2026, financial security expert Li Chang  how AI tools could extract a celebrity’s fingerprints from a single selfie. The culprit? The classic V-sign, finger pads pointed straight at the lens.

This built on work by Japan’s  which in 2017 showed that usable fingerprints could be lifted from photos taken up to three metres away. And phone camera technology has only got better since then...

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