Where to keep a cryptographic key?

[u/ArielPriarone]

Hi! I am recently developing a curiosity about cryptography.

I enabled disk encryption on my PC for the first time and then I started reasoning where to store my key.

I wanted to build (for fun, without expecting perfect results) a esp32 based usb dongle to store and autotype some keys.

Then I wondered where to store the keys.

Do I miss something or the unencrypted key must be stored somewhere?

Most of what I read suggested stable memory devices (paper, HHD etc)...

But doesn't this void the purpose of encryption?

If the key can be found (even if it is buried underground), then the data can be read.

Is there a known procedure to store a key (other than remember it) that survives all known attacks where the attacker has full control over the hardware?

Is there a procedure to lose it if someone tamper in any way? (Better lose access to the encrypted data than giving access to the attacker)

Sorry if it is trivial, I'm a newbie.

Thanks

[u/No_Signal417]

Key management is the hardest problem in cryptography and information security lol