Mobile contact discovery allows users of mobile messengers to conveniently connect with people in their address book: newly registered users can instantly start messaging existing contacts based on their phone numbers without exchanging additional information like usernames or email addresses...
In a research collaboration between TU Darmstadt, TU Graz, and University of Würzburg, we show that currently deployed contact discovery services severely threaten users' privacy...
Breaking Fixing Contact Discovery in Mobile Messengers