Couldn't it be a secondary stream to the same endpoint but using a different key...

r00fus on May 25, 2016 | parent | context | favorite | on: Is Facebook eavesdropping on phone conversations?

Couldn't it be a secondary stream to the same endpoint but using a different keying (ie, encryption with server's pubkey) mechanism (the metadata then wouldn't be E2E encrypted, but that's not covered in WhatsApp's E2E security page)?