Code obfuscation - Cybersecurity ASEE (2024)

Mobile application security toolkit

The packing method compresses the entire application to make the obfuscated code unreadable to the uninvited guest.

The instruction pattern/flow transformation technique alters common instructions made by the compiler into less common, more complex instructions that perform the same functions.

The dummy code's role is to prevent reverse engineering attacks by filling up the script with unnecessary code that does not affect the execution of the application. This approach is effective at distracting both the human eye and compilers used to gain insight into the application logic.

This code obfuscation technique aims to remove any additional context that provides more information about the application logic. Elements such as debug information and metadata can be of extreme value to an attacker. Removing them is a common practice in heightening application security.

Opaque predicate insertion involves including a piece of code that is potentially incorrect but won't execute any functions. The role of an opaque predicate is to puzzle the reader with additional statements, usually or/if-then conditional branches, that lure the attacker in the wrong direction when trying to figure out the application logic.

Arithmetic obfuscation takes simple arithmetic and logical pieces of code and replaces them with more complex equivalents.

Debuggers are tools used for code analysis, line by line, helping developers find issues within the code. Hackers, on the other hand, use debuggers for reverse engineering. Anti-debug tools are helpful in detecting the use of debuggers and preventing potential attacks. Essentially, what happens in case an app runs on a debugger is the following;

An anti-tamper tool is basically a form of application self-protection mechanism injected into the apps' code. In case of tampering detection, the application should react in any of the following actions:

The string encryption code obfuscation technique hides the strings in a managed executable. Without the use of obfuscation, the strings are readable. However, in the case of string encryption, the original value of the strings displays only when necessary – at runtime.

As the name states, this code obfuscation technique encodes strings with a custom algorithm that enables a decoder function to retrieve the original code.

This code obfuscation technique randomly shuffles routines and branches within the code without affecting code execution. It is popular among malware writers in order to avoid antivirus detection.

Code virtualization, or virtualization obfuscation, is a code obfuscation method protecting software from malicious code analysis. It replaces the code in a binary with a bytecode that is semantically equivalent. The bytecode can be interpreted exclusively by a virtual machine. This makes the revealing of the final code a tiring job for the attacker.

Control flow is one of the code obfuscation techniques that pay off the most. To protect your code, you introduce arbitrary statements and dead code, which in the end, won't execute. The decompiled code would take on the look of spaghetti logic, making the code extremely difficult to understand for the malicious party. However, it is important to note that implementing code flow obfuscation often results in affecting the runtime performance of the method to which it applies.

The functionality of the code remains intact

Although the content of the code is different, all of the functions included in the mobile application's original source code remain the same. The look and feel of the application are intact, backed up by heightened security measures.

Integrated application self-protection

The main goal of code obfuscation is to prevent attacks such as reverse engineering. Obfuscation application makes the code unreadable, demotivates hackers from advancing in their malicious attempts, and protects the mobile application from the inside by alerting the app's stakeholders about a potential security threat.

Imitation apps prevention

Code optimization

Some code obfuscation techniques are based on decluttering metadata that is not useful or code that doesn't perform any functions. This can result in a lighter application and quicker code execution.

Protection of intellectual property

Organizations and application stakeholders who want to safeguard their code from attackers and competitors should consider code obfuscation as a means of intellectual property protection. The attackers are no strangers to blackmailing industry giants in order to keep information regarding security loopholes a secret.

Depending on the techniques used, changes in code performance will vary from 0 to 80%. If we examine the effect of rename obfuscation in terms of the final performance, the change is hardly noticeable. That is the case because only the names of methods, variables, and classes are altered. However, control flow obfuscation can prove to have a significant impact on code performance. The addition of meaningless code, performing zero functions, adds weight and slows down the execution.

As discussed in the section concerning the quality of obfuscation, it is important to weigh the effort and output of code obfuscation. Not all techniques work well with different code. The goal is to find the best tradeoff between the added security layers and the potential impact on code performance.

1. What is code obfuscation?

To obfuscate a code means making it difficult to understand for the reader. Code obfuscation is the process of altering the initial code in a way that can't be interpreted by a hacker while the code remains fully functional. For a layered approach and enhanced security, use several different code obfuscation techniques on top of each other.

2. How does code obfuscation work?

Different code obfuscation techniques use different mechanisms to achieve either partial or complete obfuscation of code. Regardless of the method used, the goal of obfuscation is to make the attacker unable to comprehend the code logic. This is achieved by replacing variable names, deleting unused metadata, and other techniques that make it difficult for the hacker to tamper with your code.

3. How to measure the quality of implemented code obfuscation?

There are five factors to keep an eye on in order to draw up conclusions about the success of code obfuscation implementation. Namely, those are differentiation, strength, cost, complexity, and invisibility.

4. How does code obfuscation impact code performance?

Depending on the techniques used, changes in code performance will vary from 0 to 80%. If we examine the effect of rename obfuscation in terms of the final performance, the change is hardly noticeable. That is the case because only the names of methods, variables, and classes are altered. However, control flow obfuscation can prove to have a significant impact on code performance. The addition of meaningless code, performing no functions, adds weight and slows down the execution. As discussed in the section concerning the quality of obfuscation, it is important to weigh the effort and output of code obfuscation.

5. What are key obfuscation techniques?

6. What are the main business benefits of implementing code obfuscation?