title: What is the usage of client secret in azure active directory b2c?
body: <p>What is the usage of client secret in Azure AD B2C? The Microsoft doc only said </p>
  
  <blockquote>
    <p>If your application exchanges a code for a token, you need to create
    an application secret..</p>
  </blockquote>
  
  <p>Will the azure ad b2c encrypt the token by the client secret, or if a native app requests a token need to send the client secret to the azure ad b2c endpoint?
  And, does the client secret can be used to make only my trust native app can get the jwt then to visit my server, third part untrust app can't get the token from the b2c to visit my server? </p>
  
  <p>and what is the usage of application id uri?</p>
  
  <p>thanks.</p>