It really is the only way to be sure.OK, that's unreasonable unless you're renting from a little self-managing DIY guy like me, but you should NEVER worry about asking anybody renting a property to unequivocally prove that they own it/have the right to rent it out to you.Any landlords, property managers, or agents who would take offense to this request these days and are unwilling to make every effort/go the extra mile to establish their identities are very likely not legit.In the very small eventuality that you do find someone who is for real AND takes offense at a request to prove their identity, well, you're dealing with a moron.