Apk protection from reverse engineering - using the package name?

Question

Hi guys I just built an app, and I want top protect it from reverse engineering by preventing repackaging the app. I did the proguard solution, but still the app gets decompiled with apktool, I saw back a while an app in play store, I tried to de/recompile it and I noticed when I change the package name of that app it crashes. So I was wondering if you have any idea how did he do it

Answer 1

Posting this as an answer as it too long for a comment. There is no way you can obfuscate your code 100%. You can make it harder, but not impossible. Proguard does the work, but that's not complete obfuscation. You could use DexGuard, the commercial version of ProGuard, which makes the security tighter by increasing the difficulty. The code would get converted to .smali files, but people can still look up and edit your code.

If Proguard does not satisfy your requirements, you could write your important codes in C/C++. This is because reverse-engineering C/C++ is much harder than Java bytecode.

You could also look into options for saving the important parts of your code on a server. This would simply keep the code away from the user's device.