Why has no one made it so that smartwatches only unlock on the wrist of their owner, reading their unique heartbeat or other biometric data? This is in addition to having the owner’s phone nearby.
Officially, you can’t disable this in the settings of an Apple Watch — Apple intentionally made it such that when you put on the watch for the first time each day, it always requires a code, even if the iPhone is nearby. This is due to security policy: the watch may end up on someone else’s wrist, and the phone may just be nearby.
Moreover, every person has unique heart rhythm patterns, which include, for example, slight variations in the intervals between heartbeats, characteristics of the heart signal shape, and how the heart responds to different stresses. These microscopic differences create a unique picture” of heart rhythm that is difficult to fake or replicate. Watches have quite a lot of time, after being worn and before they are needed unlocked, to collect, process, and decide whether to unlock or not.
Hi, I'm Rauf Aliev. 