Private browsing is a common feature of web browsers on desktop platforms. This feature protects the privacy of users browsing the Internet and, therefore, is widely welcomed by users. In recent years, with the popularity of smartphones, the private browsing mode has been introduced into mobile browsers. However, its deployment on mobile platforms has not been well evaluated. To bridge the gap, in this work, we systemically studied the private browsing modes of Android browser apps. Specifically, we proposed six private rules for mobile browsers to follow by combining the mobile browsing features with the previous research on private browsing. Furthermore, we designed an automated analysis framework, BroDroid, to detect whether mobile browsers violate these rules. Also, with BroDroid, we evaluated 49 popular browser apps crawled from Google Play. Finally, BroDroid successfully identified 58 violations, some of which come from the promised capabilities of the browser. We reported our discovered issues to the corresponding developers, and four of them (Yandex Browser, Mint Browser, Web Explorer, and Net Fast Web Browser) have acknowledged our findings. Our observation may be the tip of the iceberg, and more efforts should be put into improving the privacy protections of mobile browsers.

Bluetooth Low Energy (BLE) is widely deployed and has become the de-facto communication standard in the IoT ecosystem. Naturally, the security of BLE received much attention from both researchers and attackers. In another aspect, the BLE specifications provide the security guidelines for BLE deployments. Due to various reasons, the developers do not follow the guidelines in the implementation process, which introduces the misconfiguration issue. However, identifying these BLE mis-configurations in IoT device firmware is quite challenging. In this work, we do not handle the BLE-enabled devices directly. Instead, we focus on the security misconfiguration issues in their companion mobile apps, which can reflect the deployment conditions of the corresponding devices. Further, we designed an analysis tool - BSC-Checker to detect the misconfigurations based on pre-defined checking strategies. With BSC-Checker, we conducted large-scale experiments on 4,589 apps from multiple app markets. The result shows that the BLE configurations of most BLE apps disobey at least one security rule, and the current BLE deployment status is not optimistic.