So what percentage of those billions are correctly using the ridiculously long numbers (60 decimal digits) used to represent identities (WhatsApp calls them "security codes") in that system to ensure they are actually communicating end to end? WhatsApp doesn't even inform the user of changes to these numbers by default[1] so my guess would be that practically no WhatsApp users are working end to end. WhatsApp can intercept messages at will.
I am not singling out WhatsApp here. In a usability study involving Signal[2], 21 out of 28 computer science students failed to establish and maintain a secure end to end encrypted connection.
I am not singling out WhatsApp here. In a usability study involving Signal[2], 21 out of 28 computer science students failed to establish and maintain a secure end to end encrypted connection.
[1] https://faq.whatsapp.com/1524220618005378
[2] https://www.ndss-symposium.org/wp-content/uploads/2018/03/09...