FOADA: Toward Robust Open-World Mobile App Fingerprinting

Smartphone users are susceptible to a privacy leakage attack called App Fingerprinting (AF), where traffic analysis is used to infer the apps in use. Despite packet encryption, AF attacks leverage packet size and timing information to identify apps, posing a privacy threat. However, existing attacks fail when a few apps are used concurrently, causing unsegmented traffic with app multiplexing and overlapping. The key reason is that they cannot accurately identify active time boundaries for the apps. This paper presents a novel AF attack, FOADA, the first to accurately predict both the location and label of a target app in traffic. FOADA approaches AF as an object detection problem, training a deep learning model to estimate boundary positions and classify traffic segments. Accurate boundary predictions help the model focus on the most relevant traffic segment, enhancing its classification performance. FOADA excels in handling noisy app traffic. With app multiplexing, it achieves an F1-score of 0.96 for predicting only app labels and an F1-score of 0.92 for predicting both app labels and their locations. FOADA surpasses the state-of-the-art attack PacketPrint, which achieves F1-scores of 0.80 and 0.48 in these two scenarios, respectively. The inference time of FOADA is 2,000 times faster than PacketPrint.