Biblio

The online advertising ecosystem is built upon the massive data collection of ad networks to learn the properties of users for targeted ad deliveries. Existing efforts have investigated the privacy leakage behaviors of mobile ad networks. However, there lacks a large-scale measurement study to evaluate the scale of privacy leakage through mobile ads. In this work, we present a study of the potential privacy leakage in location-based mobile advertising services based on a large-scale measurement. We first introduce a threat model in the mobile ad ecosystem, and then design a measurement system to perform extensive threat measurements and assessments. To counteract the privacy leakage threats, we design and implement an adaptive location obfuscation mechanism, which can be used to obfuscate location data in real-time while minimizing the impact to mobile ad businesses.

The online advertising ecosystem is built upon the massive data collection of ad networks to learn the properties of users for targeted ad deliveries. Existing efforts have investigated the privacy leakage behaviors of mobile ad networks. However, there lacks a large-scale measurement study to evaluate the scale of privacy leakage through mobile ads. In this work, we present a study of the potential privacy leakage in location-based mobile advertising services based on a large-scale measurement. We first introduce a threat model in the mobile ad ecosystem, and then design a measurement system to perform extensive threat measurements and assessments. To counteract the privacy leakage threats, we design and implement an adaptive location obfuscation mechanism, which can be used to obfuscate location data in real-time while minimizing the impact to mobile ad businesses.

Physical layer security for wireless communication is broadly considered as a promising approach to protect data confidentiality against eavesdroppers. However, despite its ample theoretical foundation, the transition to practical implementations of physical-layer security still lacks success. A close inspection of proven vulnerable physical-layer security designs reveals that the flaws are usually overlooked when the scheme is only evaluated against an inferior, single-antenna eavesdropper. Meanwhile, the attacks exposing vulnerabilities often lack theoretical justification. To reduce the gap between theory and practice, we posit that a physical-layer security scheme must be studied under multiple adversarial models to fully grasp its security strength. In this regard, we evaluate a specific physical-layer security scheme, i.e. orthogonal blinding, under multiple eavesdropper settings. We further propose a practical "ciphertext-only attack" that allows eavesdroppers to recover the original message by exploiting the low entropy fields in wireless packets. By means of simulation, we are able to reduce the symbol error rate at an eavesdropper below 1% using only the eavesdropper's receiving data and a general knowledge about the format of the wireless packets.