In the BillingService module, what needs to be modified to increase security?

Question

The comment for the class BillingService recommends that:

You should modify and obfuscate this code before using it.

OK, but

Answer 1

They explain it as follows:

The in-app billing sample application is publicly distributed and can be downloaded by anyone, which means it is relatively easy for an attacker to reverse engineer your application if you use the sample code exactly as it is published. The sample application is intended to be used only as an example. If you use any part of the sample application, you must modify it before you publish it or release it as part of a production application.

In particular, attackers look for known entry points and exit points in an application, so it is important that you modify these parts of your code that are identical to the sample application.

It means don't use the code as provided, change some part of it so that hackers won't be able to know what code you use.

Basically, I don't think they meant the billingService itself, but the way you use it in your application.