[abricot]

I wonder if there is any verification

[rini17]

He is assumed to have mined many coins back in the beginning and he can verify himself by spending them.

[lozf]

It's not necessary to spend to verify, the Bitcoin protocol allows a signed message to demonstrate ownership of the private key for an address.

[znpy]

They are unlikely to do so since those coins are massively looked upon and they're very careful about not disclosing their identity.