One checkmark = message delivered / Double checkmark = somebody read it. That somebody might as well be WhatApp doing a MITM The double checkmark stuff the blo

One checkmark = message delivered / Double checkmark = somebody read it. That somebody might as well be WhatApp doing a MITM The double checkmark stuff the blog talks about just means you cannot retroactively rekey already sent (old) messages. WhatApp inserting itself as a MITM can however read (and double checkmark) and new messages after they did the MITM rekeying