title: OAuth 2.0 OBO web3
body: <p>I want create a smart contract where users can record a weblink to a social profile.</p>
  <p>But i need to got the proof on chain that the user is the owner of the link.</p>
  <p>I mean i need to make the user give its credentials to proof he is the owner of the profile. And of course keeping it private.</p>
  <p>Does someone got an idea about the best way to do it ?</p>
  <p>Thanks a lot.</p>