Here&#x27;s the thread: <a href="https:&#x2F;&#x2F;groups.google.com&#x2F;forum&#x2F;#!searchin&#x2F;mozilla.dev.identity&#x2F;iframe&#x2F;mozilla.dev.identity&#x2F;KE6TAA-lgk4&#x2F;kAzM46NP4vsJ" rel="nofollow">https:&#x2F;&#x2F;groups.google.com&#x2F;forum&#x2F;#!searchin&#x2F;mozilla.dev.ident...</a><p>Basically, Persona by design needs to transmit a keypair and a signed certificate between the identity provider and the relying party. Without in-browser integration, the way this was done was using localStorage on the login.persona.org domain, making Mozilla a trusted third party. This was deemed okay as a temporary measure until in-browser support for BrowserID became commonplace, replacing the trusted third party with the user-agent.<p>Reading the thread again, my memory was a little off: possible solutions were proposed, but the conversation fell off before consensus could be reached, and no one had the time to drive any attempt to implement the change.