How code obfuscation works and why it is needed?

When it comes to protecting the code, most people feel that encryption will be a good option. Even though this will modify the data in such a way that others cannot decode it, it cannot be used unless it is decrypted. In this manner, it becomes difficult to execute the code without decryption. For this reason, most people prefer to go with code obfuscation which offers better protection and gives more flexibility with regards to protecting the code.

Let us try to understand how this can be done in different ways and protect your applications from external threats. Many people who neglect this simple aspect of programming suffer a lot in the long run as the code gets easily stolen and it can be reused by other people in the market. It is important to understand that you need to choose code obfuscation even when you are delivering an application to your client. It is enough for the client to have the executable version of the code and you need not provide the source code unless it is explicitly mentioned in the contract. In this manner, your client cannot pass on the program to other users in the market.

How does code obfuscation work?

Code obfuscation is done in different methods and it is possible to build one technique on top of the Other to offer better protection. In this manner, the code is rendered unreadable and any person who gains access to the code will not be able to use it to re-generate the source code. Let us consider some of the top techniques used in this process.

Rename Obfuscation

This is the basic method of code obfuscation and it modifies the variable and names of different functions in the program. This makes the code difficult for any person to understand and attackers will not be able to read and analyze the source code when they gain access to this program. This does not affect the execution of the program in any manner. The source code is still executable and it does not interfere with the normal working of the code. You can find this technique used for several Android and Java applications.

In simple terms, when you rename the obvious variables and methods used in the program, others will not be able to make sense of what you have written in the code. You can keep a separate source for the original code and provide enough documentation so that you will be able to make suitable changes in the future without any problems. On the other hand, if any attacker gains access to the code, the code is modified so much that they will not be able to understand the flow of the program and your source code cannot be regenerated by the attackers.

String Encryption

This method works on top of the basic renaming obfuscation method. Even after altering the variable and method names in the program, the different strings used are still readable and some experts can understand the logic by accessing the strings used in the program. To prevent such attempts, advanced programmers use string encryption methods. In this method, all the strings that are easily readable are encrypted and the strings have to be decrypted at runtime before it can be executed. In this manner, anyone who gains access to the original code will have to first understand the different variables and methods that are obfuscated and then manage to decrypt the strings in order to completely understand your code.

This is a complicated process, and most attackers give up on regenerating the code with so many hurdles. For this reason, you should always prefer to use string encryption along with renaming methods in order to offer better protection for your code. It is important to understand that this method has some drawbacks and you may have to compromise on runtime performance by some margin. As the strings used in the program have to be decrypted, it can have a small impact on the runtime performance.

Dummy Code Insertion

In this method, dummy code is inserted into the executable and it makes it very difficult for attackers to reverse engineer the code. Even when they manage to reverse engineer the code with some advanced applications, it is very difficult to analyse the code when there are so many dummy insertions.

The advantage of using this technique is that it does not affect the execution of the program in any manner. Apart from that, the dummy code also does not affect the logic of the program and you will be able to use it without any hassles.

What is the need for code obfuscation?

It is very difficult to develop a secure Android application. In this regard, you should put enough effort into making it secure and get the best out of your hard work. You should understand that attackers can still gain access to the code through various means. In this regard, you should be able to protect the code by using code obfuscation so that attackers will not be able to review and analyse the application.

The success of any program depends on the quality of its business logic. You should always aim to protect the business logic from external access. When attackers manage to gain access to your business logic and code, they will be able to repackage the application with your hard work. Not only that, they can also insert malicious code and tamper with your application in different ways. When attackers manage to insert malicious code into your program, there is a risk of losing your customer data to the attackers. This can put you in a difficult situation as your customers will lose trust in your company and there is a risk of attackers misusing the customer data.

Using code obfuscation can dramatically reduce the size of the file and make it easy for users to download the application. In this manner, code obfuscation is the best option to protect your application from various external threats.