As a layman when it comes to cryptography, I have recently been asking myself if there was a cryptographic equivalent of a family code of arms. I'm thinking of something asymmetric, that is future proof enough to hand down to another generation and that can be used to maybe access resources. If possible it should also have a graphical representation, similar to a QR code. 

Maybe I am totally tapping in the dark, though. If that's the case, please elaborate on why this is a stupid idea.