OpenID Connect (OIDC) was developed by the OpenID Foundation as an authentication protocol that verifies a user’s identity when they attempt to access a protected site. CAcert now offers a way to both authenticate and authorise Drupal with OIDC. This allows users of one of the best known and most widely used open source content management systems (CMS), used by some of the largest websites such as The Economist or the White House, to be used for single sign-on (SSO) and offers the benefits of a single login for multiple sites.