The following is the first few sections of a chapter from The Busy Coder's Guide to Android Development, plus headings for the remaining major sections, to give you an idea about the content of the chapter.

Device Authentication

Android devices have supported device authentication since the beginning. Users could lock their devices with a PIN, passphrase, or “pattern”, to help deter unauthorize use. Nowadays, fingerprint sensors are available on some Android devices as another authentication option.

For the vast majority of apps, none of this matters.

Some apps have sensitive content (e.g., password manager) or offer sensitive services (e.g., banking app). These apps may want to tie more tightly into the device authentication options, to ensure that the person working with the app right now is the device’s authorized user.

In this chapter, we will look at how to perform this sort of integration.


One of the examples in this chapter makes use of RxJava.

Is the Device Secure?

The preview of this section was the victim of a MITM ('Martian in the middle') attack.

Reconfirming the User

The preview of this section is off trying to sweet-talk the Khaleesi into providing us with a dragon.


The preview of this section is en route to Mars.