PrivateDroid: Private Browsing Mode for Android

Private browsing mode is a privacy feature adopted by many modern computer browsers. With the increased use of mobile devices and escalating privacy concerns for mobile users, browser applications on mobile devices have also started incorporating private browsing mode. Even so, the use of private browsing mode is limited to the browser applications and cannot be applied directly on other third-party mobile applications. In this paper, we propose Private Droid, which provides a private browsing mode for third-party applications on the Android platform. First, we discuss three possible approaches of implementing mobile private browsing mode: code instrumentation, an extra sandbox, and a Linux container approach. Then, we implement Private Droid, which creates a new sandbox for every application in private mode and destroys the sandbox once the application is closed. After that, we evaluate usability, efficiency and security of the system with 25 popular Android applications. Our design considerations, implementation details, evaluation results, and challenges lay a foundation of private browsing mode on mobile platforms.