No, this isn't a hint, because I already stated why it wouldn't work: thief will just use publicly available data and create deep fake to mimic the owner of the bank account.

If we had technology which could magically determine whether received data is genuine, the only safety check would be "Are you an owner? [y/n]"

> My point is we should spend our effort to solve this instead of trying to make information private.

Again, nobody sane ever have spend any effort on something without even a hint for it being possible. I am asking: what's your argument to even think it's possible?

It'd be fascinating to watch someone to try and recreate concepts from cryptography without the crypto though!