Research Article

A Blockchain-Based User Authentication Scheme with Access Control for Telehealth Systems

Algorithm 1

Subscription service contract.
function uploadSubs(, , )
if userExists  = = false
  expiretime = time.Now().Month() +
  service = Service \{, , expiretime\}
  return putState(, service)
else
  return Errorf(“the user has already exists”)
function querySubs(, )
 err, result = getState
if (err = = null)
  return result
else
  return err
function updateSubs(, )
if userExists  = = true
  expiretime = time.Now().Month() +
  service = Service \{, , expiretime\}
  return putState(, )
else
  return Errorf(“the user does not exist”)