3 results sorted by ID
Contact Discovery in Mobile Messengers: Low-cost Attacks, Quantitative Analyses, and Efficient Mitigations
Christoph Hagen, Christian Weinert, Christoph Sendner, Alexandra Dmitrienko, Thomas Schneider
Contact discovery allows users of mobile messengers to conveniently connect with people in their address book. In this work, we demonstrate that severe privacy issues exist in currently deployed contact discovery methods and propose suitable mitigations.
Our study of three popular messengers (WhatsApp, Signal, and Telegram) shows that large-scale crawling attacks are (still) possible. Using an accurate database of mobile phone number prefixes and very few resources, we queried 10% of US...
All the Numbers are US: Large-scale Abuse of Contact Discovery in Mobile Messengers
Christoph Hagen, Christian Weinert, Christoph Sendner, Alexandra Dmitrienko, Thomas Schneider
Contact discovery allows users of mobile messengers to conveniently connect with people in their address book. In this work, we demonstrate that severe privacy issues exist in currently deployed contact discovery methods.
Our study of three popular mobile messengers (WhatsApp, Signal, and Telegram) shows that, contrary to expectations, large-scale crawling attacks are (still) possible. Using an accurate database of mobile phone number prefixes and very few resources, we have queried 10% of...
RSA Weak Public Keys available on the Internet
Mihai Barbulescu, Adrian Stratulat, Vlad Traista-Popescu, Emil Simion
It is common knowledge that RSA can fail when used with
weak random number generators. In this paper we present two
algorithms that we used to find vulnerable public keys together with a simple procedure for recovering the private key from a broken public key. Our study focused on finding RSA keys with 512 and 1024 bit length, which are not considered safe, and finding a GCD is relatively fast. One database that we used in our study is made from 42 million public keys discovered when...
Contact discovery allows users of mobile messengers to conveniently connect with people in their address book. In this work, we demonstrate that severe privacy issues exist in currently deployed contact discovery methods and propose suitable mitigations. Our study of three popular messengers (WhatsApp, Signal, and Telegram) shows that large-scale crawling attacks are (still) possible. Using an accurate database of mobile phone number prefixes and very few resources, we queried 10% of US...
Contact discovery allows users of mobile messengers to conveniently connect with people in their address book. In this work, we demonstrate that severe privacy issues exist in currently deployed contact discovery methods. Our study of three popular mobile messengers (WhatsApp, Signal, and Telegram) shows that, contrary to expectations, large-scale crawling attacks are (still) possible. Using an accurate database of mobile phone number prefixes and very few resources, we have queried 10% of...
It is common knowledge that RSA can fail when used with weak random number generators. In this paper we present two algorithms that we used to find vulnerable public keys together with a simple procedure for recovering the private key from a broken public key. Our study focused on finding RSA keys with 512 and 1024 bit length, which are not considered safe, and finding a GCD is relatively fast. One database that we used in our study is made from 42 million public keys discovered when...