How to encrypt the code / part of the code so that they cannot be decompiled?

Question

Mobile development

Good afternoon!
If the application is self-written for Android. And one module has know-how and there is no desire for someone to decompile .apk and use it for their own purposes.
How to encrypt the code / part of the code, so that they could not decompile and did not affect the application's running time (resource costs)? The work of this module with a photo.
Can I steal the code on iOS?

Answer 1

None. (if something really worthwhile for you - they will steal it in any option)
Option 2:
1. Know-how - lies on your server
2. Register your program and get a copyright certificate and let them steal (then - a lawsuit).

Answer 2

None. For any tricky hole there is a bolt with a suitable thread. Everything will depend on the desire to steal. Obfuscate - but still decompile and steal. You will deliberately spoil the code - but they will still find it, debug it and steal it. If you upload from the server, they will still write a pseudo-client, pull it off and steal it.
Yes, the higher the protection technique, the higher the burglar's qualification should be. But there is no absolute protection and cannot be.

Answer 3

Write in JNI (C++, Android NDK), and try to "spoil" the code with the help of assembler so that the Hex-Rays decompiler does not take it, even in JNI you can check for the presence of methods in Java behavior, for the package name, etc. , and it is possible for the application to "crash" without any information in logcat, but still absolutely any code can be stolen with knowledge and skills, and on iOS too, if the code cannot be disassembled and debugged, then it will not work.
The only way to protect the code is to put it on the server, then the code will not be stolen, but a bot will be written, it is not known what will be easier, at first I wrote bots, then I only learned to decompile, disassemble and debug.

Answer 4

To learn the delights of encryption with a public key to get a private key and get ingenious content and run it for execution in a pseudo-isolated scope with a separation into incomprehensible what and in what places execution ... But it’s worth doing a step-by-step code execution and everything that passes will become clear and understandable ...
Therefore, the only option left is to obtain patents for "know-how", but not only in your own country, but also for others, which will cost another pretty penny, but in which case you can go to the toilet with this patent, because there are nuances that allow bypass someone's "know-how" and make your own "know-how" on its basis