There’s the concept of unclonable physical functions (PUFs) (https://en.m.wikipedia.org/wiki/Physical_unclonable_function https://en.m.wikipedia.org/wiki/Physic

There’s the concept of unclonable physical functions (PUFs) (https://en.m.wikipedia.org/wiki/Physical_unclonable_function https://en.m.wikipedia.org/wiki/Physical_unclonable_function) that can provide something like this. Some companies like Physec offer key derivation mechanisms based on PUFs that depend on the physical characteristics of the environment of the device that generates the key (e.g. the electromagnetic impedance), so an attacker needs the actual device to produce a key that matches the profile, and tampering with the device by e.g. opening it destroys its ability to generate a key due to changes in impedance. It’s a really neat concept but I don’t think anyone found a way to apply it to a human, though it should be possible (e.g. using your heartbeat).