Schneier - Interview with Signal’s New President

Long and interesting interview with Signal’s new president, Meredith Whittaker:

WhatsApp uses the Signal encryption protocol to provide encryption for its messages. That was absolutely a visionary choice that Brian and his team led back in the day ­- and big props to them for doing that. But you can’t just look at that and then stop at message protection. WhatsApp does not protect metadata the way that Signal does. Signal knows nothing about who you are. It doesn’t have your profile information and it has introduced group encryption protections. We don’t know who you are talking to or who is in the membership of a group. It has gone above and beyond to minimize the collection of metadata.

WhatsApp, on the other hand, collects the information about your profile, your profile photo, who is talking to whom, who is a group member. That is powerful metadata. It is particularly powerful—and this is where we have to back out into a structural argument ­ for a company to collect the data that is also owned by Meta/Facebook. Facebook has a huge amount, just unspeakable volumes, of intimate information about billions of people across the globe.

It is not trivial to point out that WhatsApp metadata could easily be joined with Facebook data, and that it could easily reveal extremely intimate information about people. The choice to remove or enhance the encryption protocols is still in the hands of Facebook. We have to look structurally at what that organization is, who actually has control over these decisions, and at some of these details that often do not get discussed when we talk about message encryption overall.

from Schneier on Security https://www.schneier.com/blog/archives/2022/10/interview-with-signals-new-president.html