title: How to save refresh tokens?
body: <p>I'm trying to add authentication feature to my application.
  The authentication server implements <strong>oauth 2.0</strong></p>
  
  <p>I'm not sure how to save the <strong>refresh_token</strong>. I want to save it to a file, so next time when the application starts and there is a refresh_token available, it can ask for a new <strong>access_token</strong>. The user won't need to re-login again.</p>
  
  <p>But this doesn't sound secure to me, because if someone copies my file that has the refresh_token to another computer, he can hack into my account.</p>