not a technical person so pardon my ignorance.

so we have a private key
a public key

would it be possibly to add a password to the btc protocol for validating transactions?
for example the hashed password is stored in the network itself.
so to send something would require private key, public key etc, and a password (like the encrypted wallet.dat)

the only reason i ask is because it may add another level of protection/validation and in the one in a million chance that someone else winds up with your private key they won't be able to use it. would this add extra security to the protocol?