Prihook: Differentiated context-aware hook placement for different owners' smartphones

A context-aware hook is a piece of code. It checks context-aware user privacy policy before some sensitive operations happen. We propose Prihook to address specific context-aware user privacy concerns through putting specific context-aware hooks. We design User Privacy Preference Table (UPPT) to help a user express his privacy concerns and propose a mapping from the words in the UPPT lexicon to the methods in the Potential Method Set. With this mapping, Prihook is able to (a) select a specific set of methods; and (b) generate and place hooks automatically. Hence, the hook placement in Prihook is personalized. We test Prihook separately on 6 typical UPPTs representing 6 kinds of resource-sensitive UPPTs, and no user privacy violation is found. The experimental results show that the hooks placed by PriHook have small runtime overhead.