Securing Your Mobile Apps: A Comprehensive Guide to Fortifying Android and iOS Applications Against Cyber Threats


Building an app is just the initial phase of mobile app development. There are crucial processes that follow, one being mobile app security. With the growth of the mobile app industry, cybercrimes have also grown. It is now not possible to submit an app to the app store without security measures.

Before exploring the mobile app security best practices, we need to understand why they are necessary and what app security issues exist. For perspective, consider these facts:

Why Mobile App Security? Potential Threats and Solutions

While malicious, common mobile app security threats can be addressed with simple security measures. Major issues include:

1. Faulty server controls

Communication between an app and a user happens via servers, which are primary hacker targets due to overlooked server-side security considerations by developers. This may result from a lack of mobile security knowledge, budget constraints, or cross-platform vulnerabilities.

2. The absence of Binary protection

The lack of Binary protection is also a major mobile app security risk according to OWASP. Without binary protection, hackers can easily reverse engineer an app’s code to introduce malware or create a pirated copy with injected threats. This leads to critical issues like data theft, brand damage, and revenue loss.

3. Data Storage Insecurity

One major issue often found in Mobile app security is the lack of a data storage system. Many mobile app developers tend to rely on client storage, for data, which unfortunately can be easily accessed and manipulated if a rival gains possession of the device. This poses risks such as identity theft or violation of policies, like PCI.

4. Inadequate protection for the Transport layer

The transport layer facilitates data transfer between client and server. Without properly securing Android app standards at this junction, hackers can easily steal or modify internal data. This enables severe crimes like identity theft and fraud.

5. Unintended Leakage of data

Unintended data leakage occurs when critical mobile apps are stored in vulnerable locations on a device. For example, if an app is stored where other apps or devices can easily access it, it can result in data breaches and unauthorized data usage.

What are common mobile app vulnerabilities?

By implementing proper security measures, developers can safeguard mobile apps against common vulnerabilities, protecting user privacy and information.

While not an exhaustive list, below are some of the most prevalent mobile app vulnerabilities seen in security testing:

  • Insecure data storage – Storing unencrypted sensitive data like passwords in easily accessible app locations risks theft and misuse.
  • Insufficient authentication and authorization – Flaws here enable unauthorized data and functionality access.
  • Injection attacks – Allowing untrusted data into dynamic queries can trigger injection attacks like SQL injection.
  • Unvalidated input – This can lead to exploits like buffer overflows, remote code execution, or full backend access.
  • Broken cryptography – Weak algorithms or improper implementation jeopardizes sensitive information confidentiality.
  • Side-channel attacks – Timing or power analysis attacks can expose encryption keys and other sensitive data.

How to Make Android Apps Secure?

1. Encryption of Data on External Storage

Since internal device storage space is often limited, users frequently rely on external hard disks and flash drives for extra data storage capacity. This externally stored data may contain sensitive, confidential information. However, data on external devices can be readily accessed by all apps on that device. Therefore, it is critical to encrypt externally stored data, with AES (Advanced Encryption Standard) being a commonly used algorithm.

With the prevalence of space-constrained mobile devices, external storage usage is unavoidable for most users. Yet this data remains insecure without encryption due to the open access of external storage from all apps. AES encryption provides a vital safeguard, allowing sensitive information to be safely kept and preventing unauthorized access from potentially malicious apps.

2. Using Internal Storage for Sensitive Data

Android apps have access to an internal storage directory, with file creation done in MODE_PRIVATE mode. This ensures one app’s files cannot be accessed by other apps on the device. Leveraging this access-controlled internal storage is a key authentication best practice for secure mobile app development.

3. Using HTTPS

Communication between an app and server should always be over HTTPS connections. Many Android users connect to open public WiFi, which can contain malicious hotspots. These can intercept and alter HTTP traffic, causing unexpected app behavior. HTTPS prevents man-in-the-middle attacks.

4. Using GCM instead of SMS

Originally SMS was used to push server data to apps, but today GCM (Google Cloud Messaging) is more secure. SMS lacks encryption protections and any device app can access and read SMS data. GCM uses refreshed registration tokens for client-side app authentication and server-side API keys, protecting integrity.

How to Make iOS Apps Secure?

  1. Secure Data Storage: Simplifying app architecture while improving security is best achieved by storing data in memory instead of on disk or remote servers. However, some local storage options for necessary persistent data include:
  2. Keychain: Ideal for small, sensitive data not needing frequent access. Keychain data is managed by iOS and inaccessible to other apps.
  3. Caches Directory: For non-critical data like caches that don’t require iCloud/iTunes backup.
  4. Defaults System: Convenient storage for large datasets.
  5. Networking Security: Apple prioritizes security and privacy, enforcing HTTPS connections for all network requests via App Transport Security. This prevents data interception.
  6. Limiting Sensitive Information Access: Many apps utilize sensitive user information like contacts or location. However developers should confirm that accessed data is completely necessary, only requesting essential user details. If native iOS frameworks can provide the data, storing duplicates is redundant and heightens risk.

Bottom Line

While no single measure can completely secure an app, implementing mobile app security best practices is vital for protecting user data. Today’s open digital landscape has malicious actors constantly attempting breaches, necessitating vigilant precaution from developers.

Through comprehensive security audits and adopting recommended guidelines around access controls, storage encryption, data validation, transport security, and more, the risks from external threats can be substantially reduced. However additional attacks and vulnerabilities will continue to emerge, requiring an ongoing commitment to testing and upgrading protections over an app’s lifetime.

Overall implementing app security best practices is about establishing layered defenses-in-depth to make breaches exponentially harder while limiting the potential damage from any single vulnerability. Dedicated hackers can compromise nearly any target with enough resources, but solid app security practices sideline most and provide precious time to respond to sophisticated threats. Users deserve responsive security management and maintenance that follows industry advancements, evolving alongside the nature of attacks.