Comment by vault_

How does being able to point at a database prevent land being stolen in the absence of a trusted third party? It's not like the land itself can authenticate the farmer. For the database to have any weight, there'd need to be an authority that can enforce what it says (and won't take bribes to ignore it, or collude in extorting "voluntary" transfers). If you do have such an agency, well, there's your trusted third party.