Android provides a secure architecture to protect the system and its applications. Android architecture is structured like a software stack in which each component of a layer accepts that the layer following it is secure. The following figure shows a simplified version of the Android security architecture:

Android OS is a multiuser, Linux-based platform in which each app has a different user. Each app has its own user ID (UID) in the Linux kernel that is unique. The UID is assigned by the system and is unknown to the app. Because of the unique UID, Android apps run in separate processes with different permissions. This mechanism is known as application sandboxing. The Android Application Sandbox isolates each application's data and code execution to improve its security and prevent malware. This means that under normal circumstances, you cannot have access to other application's data and other applications do not have access to your application's data. As...