>> Those persons (a judge, the police, even if robots by then) are the oracle.

they are not. The oracle is always a computer. It is a record in gov db that says you own something.

Judge and the police are the enforcers.

I assumed a basic level of abstract thinking since this is HN.

For the point I illustrated it does not matter. Everything is needed. The record somewhere will not be sufficient to get you your flat back when you return from holidays. Nor will a the police w/o a judge. Or the judge w/o having the the record to look at.

And re. "always a computer": trust me, in Germany where I live, it will not be a computer for years to come. Everything is paper here. :D