Application components
As we have briefly touched in Chapter 1, Android Security Model – the Big Picture, an Android application is a loosely bound stack of application components. Application components, manifest file, and application resources are packaged in an Application Package Format .apk file. An APK file is essentially a ZIP file formatted in JAR file format. The Android system only recognizes the APK format, so all packages have to be in the APK format to be installed on the Android device. An APK file is then signed with the developer's signature to assert the authorship. The PackageManager class handles the task of installing and uninstalling the application.
In this section, we will talk about the security of each of the components in detail. This includes the declaration of a component in the manifest file, so we prune loose ends and other security considerations that are unique to each component.
Activity
An Activity is the application component that usually interacts...
