MockDroid: trading privacy for application functionality on smartphones

MockDroid is a modified version of the Android operating system which allows a user to 'mock' an application's access to a resource. This resource is subsequently reported as empty or unavailable whenever the application requests access. This approach allows users to revoke access to particular resources at run-time, encouraging users to consider the trade-off between functionality and the disclosure of personal information whilst they use an application. Existing applications continue to work on MockDroid, possibly with reduced functionality, since existing applications are already written to tolerate resource failure, such as network unavailability or lack of a GPS signal. We demonstrate the practicality of our approach by successfully running a random sample of twenty-three popular applications from the Android Market.