Trust Is in the Eye of the Beholder

We carefully investigate humanity's intuitive understanding of trust and extract from it fundamental properties that succinctly synthesize how trust works. From this detailed characterization we propose a formal, complete and intuitive definition of trust.Using our new definition, we prove simple possibility and impossibility theorems that dispel common misconceptions, expose unexplored areas in the design of reputation systems and shed new light on the shortcomings of previous impossibility results.