  Patients living in a digitized world can now interact with medical
professionals through online services such as chat applications, video
conferencing or indirectly through consulting services. These applications need
to tackle several fundamental trust issues: 1. Checking and confirming that the
person they are interacting with is a real person; 2. Validating that the
healthcare professional has competence within the field in question; and 3.
Confirming that the healthcare professional has a valid license to practice. In
this paper, we present VerifyMed -- the first proof-of-concept platform, built
on Ethereum, for transparently validating the authorization and competence of
medical professionals using blockchain technology. Our platform models trust
relationships within the healthcare industry to validate professional clinical
authorization. Furthermore, it enables a healthcare professional to build a
portfolio of real-life work experience and further validates the competence by
storing outcome metrics reported by the patients. The extensive realistic
simulations show that with our platform, an average cost for creating a smart
contract for a treatment and getting it approved is around 1 USD, and the cost
for evaluating a treatment is around 50 cents.
