title: Best practice to authenticate 2 machines in a M2M environment
body: <p>I have multiple tiny Linux <em>embedded servers</em> on Beaglebone Black (could by a RaspberryPi, it makes no difference) that need to exchange information with a <em>main server</em> (hosted on the web). </p>
  
  <p>Ideally, each system talks to each other by simple RESTful commands - for instance, the main server sends out new configurations to the embedded servers - and the servers send back data.
  Commands could be also issued by a human user from the main server or directly to the embedded servers.</p>
  
  <p><strong>What would it be the most "standard" way of authentication of each server against each other?</strong> I'm thinking OAuth, assuming that each machine has its own OAuth user - but I'm not sure if that is the correct pattern to follow.</p>