Nour Regarding point 1. Actually Signal Protocol, which WhatsApp uses, has a hash verification system implemented that signs keypairs. A potential takeover can be detected instantly with zero effort; heck: you can already get WhatsApp to generate a warning on its own, the function to notify about a keychange is included in the normal user app as well :) But yes it would require an extra check in the app if the key changes for enhanced security - and that would take up some dev time. The verification is simply one API-call and a one-time confirmation in the app until the code changes. (Which also happens upon reinstalling WhatsApp or getting a new phone.)
So thereāre absolutely opportunities there. :)
The only thing that might potentially be hard (but not impossible) to detect in a user friendly way is a MitM-attack upon first verification, but for that to happen: someone must have a deeply compromised phone and thus itād probably be childs play already to monitor the chat with bunq from the bunq app itself and thus no difference in that respect. :P
I doubt itāll happen by the way, but I feel itād be very nice to have a decent chat method like WhatsApp or Signal instead of the in-app chat and it offers tons of UE-bonuses. I understand the request being made. However, maybe instead of doing a WhatsApp-channel: the in-app chat could be improved drastically? :) I vehemently disagree itās near perfect, thereās a lot of room for improvement for multiple reasons. But as this topic is specifically about WhatsApp-support, I wonāt pull it offtopic to discuss that unless the OP would be open to it/see it as a fair compromise. :)
