Summary Of Chapter 2 (Android Security Design and Architecture)
This chapter gave an overview of the security design and architecture of Android. 
We introduced the Android sandbox and the permissions models used by 
Android. This included Android’s special implementation of Unix UID/GID 
mappings (AIDs), as well as the restrictions and capabilities enforced throughout the system.
We also covered the logical layers of Android, including applications, the 
Android Framework, the DalvikVM, user-space native code, and the Linux 
kernel. For each of these layers, we discussed key components, especially those 
that are security related. We highlighted important additions and modifications 
that the Android developers made to the Linux kernel.
This fairly high-level coverage of Android’s overall design helps frame the 
remaining chapters, which dive even further into the components and layers 
introduced in this chapter.
The next chapter explains the how and why of taking full control of your 
Android device. It discusses several generic methods for doing so as well as 
some past techniques that rely on specific c vulnerabilities.