As more mobile apps become available to the customers, these applications gain popularity thanks to their many features that enhance the user experience. However, in recent years, many software applications have started processing sensitive information such as payment data or patients’ health records. Consequently, developers started experiencing many challenges regarding cyber crimes as more mobile software applications became a convenient tool for hackers. For example, data breaches cost the US businesses millions of dollars annually along with irreparable harm to company reputations. Thus, every mobile application has to be carefully developed and constantly monitored to minimize cybersecurity threats. In order to guarantee the highest levels of security for the customer, every stage of the development process requires careful attention to details.

Mobile application security consists of multiple stages that include ensuring the safety of sensitive information stored locally, avoiding data interception through network channels, and protecting your application from hacks and malicious code. Hackers employ a number of different techniques to break into your application such as reverse engineering of your compiled binary, intercepting API calls, or hacking poorly implemented APIs. To defend yourself from these attacks, here are the most effective mobile security strategies you need to consider.

Mobile Source Code Obfuscation and Binary Hardening

Your application’s compiled binary file is uploaded to publicly available stores where anyone could download it, including malicious users who try to discover your application’s source code. A popular method called reverse engineering involves decompiling the code to reveal intellectual property such as hardcoded API keys, algorithms and processes used, or any security weaknesses.

First of all, you have to ensure that your mobile application’s code is thoroughly obfuscated. Use professional obfuscation software, such as ProGuard or R8 in case of Android development, and configuration script for iOS development to convert the source code into encrypted classes and methods that cannot be understood by malicious individuals. Moreover, harden your compiled binary file with application self-protection that includes monitoring whether the app is running in an unauthorized environment.

High-Level Data Encryption of Local Storage Files

It cannot be stressed enough that physical theft or malicious attack targeted at hardware is quite common. The assumption that a lock screen provided by a mobile device’s operating system is an adequate safeguard for your data is completely wrong. Every piece of sensitive information, including personal authentication tokens and identifiers should be stored in an encrypted form.

Never use unencrypted files, plaintext files, or plain text storage for storing any sensitive data on your mobile application. iOS mobile applications can use Apple Keychain service for encrypting data, and Android apps should employ the keystore system and encrypt storage by using EncryptedSharedPreferences. If the attacker tries to decrypt such data, he will fail due to encryption using unique device’s cryptography keys.

Mobile Network Communication Security with SSL/TLS Pinning

Frequent switches of mobile phones from Wi-Fi hotspot to cellular data makes mobile application more susceptible to a MitM attack as hackers could monitor your network traffic and steal any sensitive data transmitted over the Internet.

Always communicate with your servers using a fully encrypted channel based on the HTTPS protocol and TLS v.1.3 or later. However, an experienced hacker can install his own certificate on your mobile device and bypass the SSL certificate validation check. Implement SSL/TLS pinning in your mobile application to mitigate such attacks as well as prevent man-in-the-middle attacks.

Protect APIs by Using Secure Authentication Protocols

While mobile apps have lots of functionality that is designed for receiving user input, the true data processing is usually done by your cloud-based servers, which communicate with the mobile app through APIs. A malicious person can perform MitM attack directly on the cloud API without interacting with the mobile frontend client of your application.

To prevent such attack, first of all, use OAuth 2.0 or JSON Web Token for authenticating requests. Secondly, ensure that the token is expired shortly after issuance and requires refreshing. Finally, verify the validity of user’s account and permissions for using certain APIs on the backend side of the application rather than in mobile client.

Malicious Reverse Engineering Prevention by Detecting Rooted or Jailbroken Devices

The action of rooting Android or jailbreaking iOS device allows users to gain root privileges on their devices disabling all kinds of security guardrails that protect users from malware. While this gives additional opportunities for customization of the device, the mobile application cannot be guaranteed any security. Applications can access all data of the device and perform actions that they could not have normally performed on non-rooted devices.

Before making a sensitive request to your backend server, determine whether the application is run on a compromised device by employing Google Play integrity API or App Attest for iOS to check the integrity of the environment. Based on the result, take appropriate steps to secure your mobile application.

Minimizing System Permissions Request and Data Exposure

Many rich APIs available in mobile devices allow interaction with the camera, microphone, GPS, or other hardware components. However, requesting permission for such functionality when it is unnecessary makes your application more susceptible to attacks due to expanding its attack surface.

You have to implement your application by following the least privilege principle. Instead of requesting access to entire photo albums, ask only for specific media. Do not request permissions for things that are not needed. Moreover, be especially cautious when implementing third-party software, as the biggest data breaches usually happen because of vulnerabilities in external packages.

Automated Security Testing of Application with CI Pipelines

Cybercrime landscape changes rapidly. What seemed safe yesterday may become very vulnerable today. Therefore, ensuring the high level of security of your mobile application during its development and throughout the lifecycle should include regular security testing of the app.

For that purpose, you should implement automated static and dynamic application security testing and continuous integration and delivery pipelines. You should regularly invite external cybersecurity experts to perform manual penetration testing to emulate a real hacker’s attack on your mobile application.

FAQ

Why Is Code Obfuscation So Important for Mobile Apps?

Mobile applications can easily be reverse engineered. As a result, hackers can easily discover internal processes used by the application, hardcoded API endpoints and authentication tokens, and many other useful pieces of information to break into your mobile application. Obfuscation of code solves this problem by renaming classes, methods, and variables into random meaningless string characters.

Is It Dangerous Running Mobile Application on Jailbroken/Roote Device?

Running mobile application on rooted or jailbroken device makes it lose all protections provided by device manufacturer. Hackers can easily gain root access to the application and access any sensitive information stored locally. Therefore, you should always verify whether the app runs in such environment.

How Does SSL/TLS Pinning. Your mobile application can be easily decompiled, which means that any information contained in it can easily be extracted by an attacker. You should never store any sensitive information in your application but retrieve it securely after successful user authentication.

What Is the Difference Between Static and Dynamic Testing of Applications?

Static application security testing is analyzing the application source code looking for vulnerabilities. Meanwhile, dynamic testing is analyzing how an application reacts to different types of cyberattacks.