Why Code Obfuscation Isn’t Enough to Protect Mobile Apps

For many businesses, mobile applications are integral to operations and customer engagement. However, the rise of mobile apps has also heightened the risk of intellectual property (IP) theft, putting revenue, brand reputation, and other critical aspects at risk. Attackers typically attempt to reverse-engineer a mobile app through:

1. Decompiling: Attackers use decompilers to convert the app’s binary code back into human-readable source code.
2. Analyzing code: They analyze the decompiled code to understand its structure, logic, and functionality.
3. Modifying code: Attackers can then modify the code to remove licensing checks, add malicious code, or extract proprietary algorithms and assets.
4. Repackaging: The modified code is recompiled and repackaged into a new app that can be distributed as an unauthorized or pirated version.

While code obfuscation is a common technique for safeguarding apps, it is insufficient as a standalone measure. Let’s explore why leading mobile app developers recognize that relying solely on code obfuscation techniques isn't sufficient and discover the multi-layered approach to effectively protecting their apps.

The basics of code obfuscation

Code obfuscation involves making the source code difficult to read and be understood by humans. It typically includes renaming variables, classes, and methods to non-meaningful names. Many developers stop at name obfuscation, for example, turning a function name like `calculateTotal` into `a1B2C3`. While this method can deter casual scrutiny, it alone doesn't alter the underlying logic of the code, eventually leading to reverse engineering with slightly more effort.

Hackers can still decompile and analyze the obfuscated code to understand its functionality. Here’s why: Despite obfuscation, the logical structure of the code remains intact. This is similar to changing the names of characters in a book without altering the plot. An experienced hacker can still follow the story. In addition, modern decompilers and reverse engineering tools can easily navigate obfuscated code. These tools are designed to understand code logic, regardless of naming conventions.

The need for comprehensive code hardening

To truly protect a mobile app, developers must implement multiple layers of security. A layered approach to mobile app security addresses multiple vulnerabilities, making it harder for attackers to exploit the app. Each layer provides a different type of protection, such as various obfuscation techniques and real-time threat detection, ensuring comprehensive defense. This multifaceted strategy significantly reduces the risks and enhances the overall security of the app.

For example, beyond the basic name obfuscation technique described above, developers might employ a variety of code hardening techniques, such as:

1. Control flow obfuscation: This technique alters the code's control flow, making it harder for decompilers to understand the sequence of operations. It's like scrambling the chapters of a book, making it difficult to follow the narrative.
2. Arithmetic obfuscation: This involves replacing simple arithmetic operations with complex, equivalent expressions. This adds a layer of confusion, making it harder for bad actors to reverse engineer the calculations.
3. String & class encryption: Encrypting strings and class names adds another layer of security, making it difficult for attackers to decipher critical parts of the code.
4. Resource encryption: Encrypting resources such as images and configuration files protects against extraction and misuse.

Let’s look at how mobile app developers at leading global organizations are using these techniques and more to protect their app code.

A real-world approach to layering security protections

The most effective strategy for securing mobile apps involves layering various code hardening techniques and real-time defenses:

• Obfuscation: Use advanced obfuscation methods described above, beyond simple name changes
• Encryption: Encrypt sensitive parts of the code and resources
• RASP (Runtime Application Self-Protection): Implement mechanisms that allow the app to detect and prevent real-time attacks.

Combined with comprehensive threat monitoring, development teams can defend their applications against even the most complex, emerging threats. Let’s look at how some of the leading developers are protecting their mobile applications using this approach.

Protecting a leading banking app from malicious actors

Recent research by Guardsquare found that, surprisingly, only 48% of organizations reported having up-to-date company policies that outlined security requirements. Organizations may focus on the minimum requirements due to a lack of time and available skills to create their desired security process for mobile apps. This is alarming in financial services apps, given the high stakes involved, including monetary fraud and reputational damage.

Knowing the risks, one of the 50 largest U.S. banks implemented a multi-layered security approach to protect its mobile app's intellectual property and customer data. Facing the challenges of securing their Android app against tampering, repackaging, and malicious code insertion, the bank's development team employed advanced security techniques. They used code hardening as the first line of defense, protecting their applications and libraries and making them difficult to tamper with.

The bank also integrated RASP to detect and prevent real-time attacks, especially on rooted devices. Regularly updating security configurations, the development team ensured their app stayed resilient against new threats. This comprehensive security approach not only prevented reverse engineering but also helped the bank meet compliance requirements for mobile payments, providing peace of mind for both the bank and its customers.

Safeguarding patented innovations for a leading Android application

One of the longest-maintained AI apps on Google Play, an award-winning Android app allows users to manage device settings automatically based on customizable conditions. Concerned about piracy and the security of the app, the developer implemented a multi-layered approach to protect both intellectual property and user data.

The developer employed advanced code obfuscation, RASP, and real-time threat monitoring to secure the app against tampering, reverse engineering, and unauthorized modifications. These measures not only safeguarded the app’s four patented innovations, but also ensured a secure and seamless user experience. By stripping unnecessary code and monitoring threats, the developer maintained the app's performance and security, providing users with a reliable and privacy-focused solution.

Keeping photo and video copyright pirates at bay

A leading software company designs top mobile video and photo imaging software for iOS and Android, widely used by artists in Hollywood and Bollywood. Their Android app faced continuous attacks aimed at pirating the paid app and distributing unauthorized copies, leading to revenue loss and brand damage. The existing Google Play licensing service was insufficient as attackers bypassed the licensing check to copy and pirate the app.

To counter these threats, the development team adopted a multi-layered security approach, enhancing code obfuscation, encrypting assets, and implementing RASP. These measures significantly increased the difficulty for attackers to clone or repackage the app. By combining these advanced security techniques, the company effectively protected its intellectual property, maintained app stability, and ensured a secure and reliable user experience. This comprehensive approach not only safeguarded the app but also preserved the company's reputation and revenue stream.

Obfuscation is only one part of comprehensive mobile app security

Relying solely on code obfuscation to protect mobile applications might deter amateurs, but it won't stop determined intruders. The stories above demonstrate the effectiveness of implementing a layered security approach, combining multiple code hardening techniques with protections at runtime and real-time threat monitoring. Failing to protect mobile apps adequately from threats such as piracy, reverse engineering, and unauthorized modifications can lead to significant financial losses, damage to brand reputation, and compromise of user privacy.

This approach is essential to safeguarding your app's integrity, ensuring that attackers can’t easily reverse-engineer and steal code or other proprietary assets. Keeping the right defenses in place for mobile apps can cement their position as a crucial part of business operations, preventing costly attacks and reputational damage.