A protocol for data exchange with free samples using smart contracts

Distrust between data providers and data consumers
is one of the main obstacles hampering digitaldata
commerce to take off. Data providers want to
get paid for what they offer, while data consumers
want to know exactly what are they paying for before
actually paying for it. In this paper, we summarize
a protocol that overcomes this obstacle by building
trust based on two main ideas. First, a probabilistic
verification protocol, where some random samples of
the real dataset are shown to buyers in order to allow
them to make an assessment before committing any
payment; and second a guaranteed, protected payment
process, enforced with smart contracts on a public
blockchain, that guarantees the payment of the data if
and only if the data provided meets the agreed terms,
and that refunds honest players otherwise.