

Some of the world’s most popular mobile messengers (with billions of users) like WhatsApp perform contact discovery by regularly uploading and storing the users’ entire address books, while more privacy-concerned messengers like Signal transfer only short hashes of phone numbers or rely on trusted hardware. 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. What is Mobile Contact Discovery & Why Should I Care? Attacks on WhatsApp, Signal, and Telegram in the News German IT-Security Award 2020 for their work on mobile private contact discovery. News Second Prize in German IT-Security Award 2020Ĭhristian Weinert, Thomas Schneider, Matthias Senker, Daniel Kales and Christian Rechberger won the second prize in the 8. This website is also available in German. Mobile (Private) Contact Discovery Breaking & Fixing Contact Discovery in Mobile Messengers Mobile (Private) Contact Discovery | Breaking & Fixing Contact Discovery in Mobile Messengers Skip to the content.
