The metadata is actually quite important.
Sure, chances are it’s a “pending WhatsApp message” notification, but not the actual contents of the message.
However, with enough metadata and by surveying traffic from WhatsApp data centers, someone could see User A accessed WhatsApps service, which generated a WhatsApp notification for User B.
That might just be a coincidence, but with enough data and time, the probability that User A is talking to User B can be increased.
If it also shows that Users C, D and E also get notifications at the same time, it is likely that all those users are in a group chat together.
It’s called a timing attack.
And perhaps it isn’t enough evidence to stand up in court, it can help build the profile of the users, and guide investigations to other possible accomplices.
I realize that sometimes metadata can be aggregated in nefarious ways. sometimes, however, it’s useless. currently, however, it contains all of the unencrypted contents of the notification itself, not just the metadata, and my point is that’s it’s better to take the step of encrypting the notifications themselves to at least protect that data.
The metadata is actually quite important.
Sure, chances are it’s a “pending WhatsApp message” notification, but not the actual contents of the message.
However, with enough metadata and by surveying traffic from WhatsApp data centers, someone could see User A accessed WhatsApps service, which generated a WhatsApp notification for User B.
That might just be a coincidence, but with enough data and time, the probability that User A is talking to User B can be increased.
If it also shows that Users C, D and E also get notifications at the same time, it is likely that all those users are in a group chat together.
It’s called a timing attack.
And perhaps it isn’t enough evidence to stand up in court, it can help build the profile of the users, and guide investigations to other possible accomplices.
I realize that sometimes metadata can be aggregated in nefarious ways. sometimes, however, it’s useless. currently, however, it contains all of the unencrypted contents of the notification itself, not just the metadata, and my point is that’s it’s better to take the step of encrypting the notifications themselves to at least protect that data.