Analyzing Locality of Mobile Messaging Traffic using the MATAdOR Framework

TL;DR

This paper presents a large-scale analysis of mobile messaging traffic locality, revealing centralized server architectures that impact privacy and communication paths, using a novel measurement framework that is application-transparent.

Contribution

It introduces the MATAdOR framework for analyzing messaging traffic without modifying apps and provides insights into the centralized nature of messaging service architectures.

Findings

Messaging servers are highly centralized in single countries.

Traffic often deviates from direct communication paths.

Centralization enables potential interception and censorship.

Abstract

Mobile messaging services have gained a large share in global telecommunications. Unlike conventional services like phone calls, text messages or email, they do not feature a standardized environment enabling a federated and potentially local service architecture. We present an extensive and large-scale analysis of communication patterns for four popular mobile messaging services between 28 countries and analyze the locality of communication and the resulting impact on user privacy. We show that server architectures for mobile messaging services are highly centralized in single countries. This forces messages to drastically deviate from a direct communication path, enabling hosting and transfer countries to potentially intercept and censor traffic. To conduct this work, we developed a measurement framework to analyze traffic of such mobile messaging services. It allows to conduct automated experiments with mobile messaging applications, is transparent to those applications and does not require any modifications to the applications.