Developing a successful mobile app requires following security best practices. Attackers consistently search for ways to exploit security issues, and breaches in data can negatively impact your customer experience, reputation, and bottom line. By following mobile app security best practices, you’ll be prepared to launch a successful mobile app that keeps both your users’ and the company’s data safe. Read on to learn the top 13 security best practices you can use as a developer to reduce security bugs and defend your mobile app against security breaches.

1. Encrypt Your Source Code

When it comes to mobile app security, you need to encrypt your source code. This will help to prevent attackers from accessing and modifying your code, which could potentially lead to them reverse engineering attacks or exploiting security issues. According to industry research, 82% of mobile app security bugs appear in the source code. By encrypting your source code, you can render the code unreadable by attackers and prevent damaging security incidents. As a developer, It’s also considered a best practice to sign your source code during mobile app development.

2. Use a Code-Signing Certificate

In addition to encrypting your source code, you should validate the authenticity of the code by using a code-signing certificate. This allows you to digitally sign your code with a private key, while also publishing a public key for users to view. A code-signing certificate signals that your mobile app is genuine, comes from a trusted source, and has not been tampered with. Since malware can be distributed by impersonating legitimate sources, this certificate reassures users about the validity of a mobile app. However, code-signing certificates are only valid for one to three years, so renew your certificate regularly.  

3. Implement File-Level & Database Encryption

Mobile apps often store unstructured data in a local file system or a database within the device storage. Without encryption, attackers can potentially access the sandbox environment, posing a significant security risk. By encrypting this data, you can reduce your risk. Likewise, to prevent attackers from accessing sensitive information, you can implement mobile app data encryption with SQLite Database Encryption Modules or use file-level encryption across multiple platforms. Whichever method you choose, make sure that you encrypt all sensitive data before storing it on your server or in your database. In addition, always use the latest cryptography techniques and perform penetration testing on your mobile app before it goes live to ensure seamless security. 

4. Utilize the Latest Cryptography Techniques

In order to keep your mobile app safe from attackers, use the latest security algorithm possible. Since attackers have a habit of trying to break the older versions of encryption, using the latest version of an algorithm helps add an extra layer of security to your mobile app. One of the most popular encryption algorithms is called Advanced Encryption Standard (AES). AES consists of a symmetric key algorithm, which means that the same key encrypts and decrypts the data. Different versions of AES encryption can be used, such as 512-bit encryption, 256-bit encryption and SHA-256 for hashing. 

5. Leverage Pen Testing

Testing your code for security issues is another important step in securing your mobile app and ensuring compliance with security frameworks. If attackers were to gain access to sensitive customer data or company intellectual property within your mobile app, it could lead to significant and damaging security breaches. By performing regular and thorough penetration tests, you can identify and resolve these security bugs before they wreak havoc on your mobile app and your compliance certifications. To ensure success and take extra work off your plate, leave this critical testing up to experts like NowSecure, a leading provider of successful and repeatable penetration testing.  

6. Secure Data in Transit

When sending data from a mobile device to server-side endpoints, attackers can potentially intercept the HTTP communication. There are several ways to secure this data in transit, including Transport Layer Security (TLS) and Certificate Pinning. TLS originally evolved from Secure Socket Layers (SSL), and this technique enables you to encrypt data in transit using public key cryptography. While TLS does not actually secure the data on end systems, it prevents data access during digital transit. Certificate Pinning uses a set of public keys to cross-check whether a digital certificate corresponds with the domain name that it’s claiming. When choosing a method to secure your data in transit, consider the needs of your mobile app, the sensitivity of your data, and potential security issues. 

7. Only Use Authorized APIs

In the case that you must use third-party services when developing your mobile app, make sure to leverage authorized APIs. APIs that are not authorized for use on a specific platform, such as Android or ioS, can unintentionally grant an attacker privilege and put your data at risk. Using unauthorized APIs can also get your app rejected and removed from app stores. Likewise, make sure to follow the specific platform guidelines for authorized APIs for maximum security and compliance.  

8. Ensure High-Level Authentication

With multiple users accessing your mobile app, you need to establish a sound method for authentication. You can do this by updating strong alphanumeric passwords every three to six months, using multi-factor authentication or even biometric authentication. While biometrics are generally more secure than passwords, they are also more expensive and difficult to implement. Regardless of the method chosen initially, regularly review your authentication methods and make changes as needed to keep your app safe.

If you have to store sensitive data, avoid storing the data on the device itself.

9. Secure the Backend

With all of the sensitive data for your app stored in the backend, you don’t want this data falling into the wrong hands. Encrypting all of your data at rest can help prevent attackers from being able to read the data, even if they were able to gain access to the backend. It’s also important to verify that all of your APIs support the mobile operating system. Lastly, using high-level authentication can protect your app from unwanted users gaining access to your sensitive data and functionality. 

10. Be Careful with Third-Party Libraries

While third-party libraries can save time and effort by using pre-written code, they can also introduce serious security risks. Since the code was not written by you, it may contain security bugs that can be exploited by attackers. For instance, the communication functionality of Log4j had a security bug that allowed attackers to inject code into the logs. And, this security risk went undiscovered for several years from 2013 to 2021. To prevent this from happening to your mobile app, make sure to use code from trusted sources, such as controlled internal repositories, and exercise policy controls during acquisition. Even without using third-party libraries, attackers can potentially gain access to your code. And, that’s where tamper detection comes into play. 

11. Deploy Tamper Detection

Tamper detection alerts you when someone tries to tamper with your code or inject malicious code. By deploying active tamper detection mechanisms, you can ensure that the code will not function at all if modified. This makes it more difficult for attackers to modify your code and keeps you in the know about any potential attempts at tampering with your code. There are many ways to detect tampering, but some common methods include checksumming, digital signatures and code obfuscation. 

12. Minimize Storage of Sensitive Data

Storing sensitive data always poses a certain level of risk, so try to avoid or at least minimize the amount of sensitive data being stored. If you have to store sensitive data, avoid storing the data on the device itself. Consider using an encrypted data container or key chain rather than storing it locally. Likewise, using an auto-delete feature can also help to confirm the removal of sensitive data as soon as you no longer need the information. 

13. Practice Continual Testing and Updating

Securing your mobile app takes constant vigilance. As new threats emerge, new solutions are needed. While it can be tempting to focus on the aesthetic appeal and usability of the app, guaranteeing ongoing security is a significant differentiating factor for success. Investing in a comprehensive mobile app testing solution can keep up with these threats for you, automating testing within the CI/CD process. By integrating testing directly into the mobile development pipeline, you can speed your app to market from start to finish in a matter of weeks. 

NowSecure provides best-in-class mobile app security automation, and we offer a free security assessment to help mobile apps like yours. 

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