Security Best Practices for Developing Secure Mobile Apps

Alt text: Security Best Practices for Developing Secure Mobile Apps

Mobile applications are a regular part of mobile phone users’ lives. Be it for entertainment, education, business, or other daily activities, people use a lot of mobile apps. Companies interact with their customers & clients via mobile apps. Even governments use many apps to provide services to their citizens. As a result, mobile apps are now an attractive target for those looking to gain unauthorized access to sensitive information or commit fraud. Hence, it has become more important than ever to incorporate the best security into mobile apps. Apps developed with security in mind will safeguard not only a user’s data but also a company’s/government’s reputation.

Still, many companies are not following best practices when it comes to application security. It has resulted in a huge problem because most apps have at least one high-risk security vulnerability.

Mobile app developers must make security a priority. In this blog post, we will learn about the various security best practices for app development.

Table of contents

• Why is secure app development necessary?

• Security best practices for developing apps

Why is secure app development necessary?

A security aspect ignored during app development can turn into a security bug or a vulnerability later and can make an app insecure. Insecure apps have several risks and issues associated with them, such as:

1. Reverse engineering

Anyone who wants to gain unauthorized access to the insecure app can use reverse engineering techniques to alter the source code of the app, decrypt the encryption algorithms in use, etc. Attackers can use the code a developer wrote against the developer, which is a severe security risk.

2. Compliance issues

Insecure apps do not comply with rules and regulations of data protection and privacy, such as GDPR (General Data Protection Regulation), DPDPB (Digital Personal Data Protection Bill), etc. It can result in regulatory penalties as well as financial losses for a company.

3. Risk of illegal activities

Most apps store personal information of users, such as login credentials, bank details, etc., to enhance user experience. If apps are insecure, attackers can use them to:

• introduce malware into devices to steal sensitive data, such as passwords to commit fraud

• steal intellectual property and distribute it without consent

• harm individuals, companies, or even a country

4. Trust issues

Customers and clients fear that they will lose their sensitive data if they use less secure apps. Hence, they may lose trust in a company or a brand if its apps are prone to security threats. This can result in an irreversible loss of reputation and revenue for the company/brand.

5. Discarding the apps

Statistics reveal that over 30% of users uninstall apps due to security vulnerabilities and issues in the apps. If an app contains any security risks, it may be removed from the official app stores of various companies or banned by the concerned government. Then, the effort and time put into making the app will go in vain.

Image caption: Risks and issues associated with insecure apps

Alt text: Risks and issues associated with insecure apps

To avoid all the above issues, it is extremely necessary that developers follow the best security practices for developing apps. Secure application development will make the digital world safer for all.

Security best practices for developing apps

An app developer needs to utilize the following security best practices to develop apps:

1. Write proper code

The language and code used to create apps needs to be written with proper syntax & semantics. Properly written code can help developers protect apps from common attacks like cross-site scripting, SQL injection, etc.

2. Develop and use their own libraries

Third-party and open-source libraries may not have the security standards that need to be incorporated into apps. The libraries may contain security bugs or malware. Attackers can take advantage of known vulnerabilities in those libraries to compromise the security of apps. To avoid that, developers need to develop and use their own libraries.

While developing libraries may be time-consuming, it can help reduce security risks.

3. Use proper APIs

To provide utmost user experience, apps are integrated with Application Programming Interfaces (APIs) that enable them to communicate with each other. Attackers frequently target APIs as possible weak links. Hence, to develop secure apps developers need to:

• limit the use of APIs

• develop and use their own APIs instead of third-party APIs

If companies require complex features in apps that are beyond their developers’ area of expertise, they can choose reputable vendors for development. In that case, the companies must continuously monitor and maintain integrations and keep a close eye on service updates.

4. Code obfuscation

After writing proper code, app developers can obfuscate the code to secure their apps. Code obfuscation involves processes such as encrypting a part of or all of the code, giving meaningless names to classes and variables, adding unnecessary code to an application binary, etc.

Obfuscating the code will discourage attackers who try to decipher or steal an app’s code. They will have to put in a lot of effort to analyze the code, comprehend the working of its algorithms, and reverse-engineer the original source code. Most attackers will not take that much trouble to attack an app with obfuscated code.

5. Encrypt data

Developers need to encrypt all the data that apps use (like source code, user information, etc.) and exchange. Data encryption converts data from plain text to ciphertext, which is an incomprehensible format. Data is encoded (transformed) using what is referred to as a "key," which is a piece of data produced by a cryptographic algorithm and typically consists of numbers and/or letters (a set of rules). Only a person with the decryption key can read encrypted data and convert it back into readable form. Hence, even if attackers steal the data, they cannot easily use it to compromise an app’s security or harm the app’s user.

6. Use signature-based permissions

To share data between two apps that developers own or are in control of, they need to use signature-based permissions. These permissions check that the apps accessing the data are signed with the same signing key, rather than requiring user confirmation. An app should ask for the minimum number of permissions that are required for it to operate properly, and developers need to check and remove permissions that their app no longer requires. This will help reduce unauthorized access to data and provide app users with a simple & safe experience.

Alt text: Secure mobile app development

7. Store data securely

Some apps may need access to sensitive user data. Users will only allow an app to access their data if they have faith that the app will handle their data safely. Therefore, developers need to develop apps in such a way that they store data securely.

Developers should develop apps in such a way that all private user data is stored within the device's internal storage and sandboxed per app. Those apps should be denied permission to view these files, and other apps can't access the files. Also, when an app is uninstalled, the device should delete all files that the app saved within its internal storage.

Sensitive data needs to be stored on the server side to avoid unauthorized access to data in the event of:

• loss or theft of a mobile phone

• jailbreaking or rooting a mobile phone

8. Improve network security

Often, companies and developers do not focus on network security during app development. Just encrypting and securing data at the generation and storage points is insufficient. Data needs to also be protected in transit by sending & receiving it securely using a VPN tunnel, SSL, TLS, HTTPS communication, etc. This will stop unauthorized access to data through attacks such as packet sniffing and man-in-the-middle attacks.

9. Testing and security audits

Developers need to continuously test their apps at every stage of development and even after the app is deployed. Focussing on security aspects is made easier for the developers by running a series of automated and manual penetration tests on mobile apps. Spending time on problem remediation and problem mitigation after issues have been identified is even more crucial. It is always a good idea to have an external security audit performed, even if companies have an internal security team. Businesses should select a reliable and reputable mobile app security testing company to audit their apps at least once every quarter.

10. Build the best development team

Companies should hire the best app developers that integrate AppSec (Application security) and DevSecOps (Development, Security, and Operations) in the app development process.

AppSec is the process of creating and maintaining security features inside apps and DevSecOps is the process of integrating security initiatives at every stage of the Software Development Life Cycle (SDLC) to develop secure apps. Security measures should be implemented at the application level by considering:

• Security during development

• Security after deployment

DevSecOps can help to detect security vulnerabilities at every stage of the SDLC. Developers can then fix those vulnerabilities quickly.

The best development team needs to use OWASP standards for developing secure apps and also ensure that their app fulfills all compliance and regulatory requirements.

11. Regularly update apps

Although manufacturers of operating systems and phones frequently implement various security measures, developers cannot fully rely on those measures to keep their apps secure. By taking care of security at the application level, developers can lessen their dependence on platforms & devices for safety and security. Hence, developers need to regularly update their apps and install security patches, regardless of updates for the phone and OS. This will reduce the number of expose vectors and make their apps more secure.

While we have covered most security best practices for app development in this blog post, security is a vast field and app developers need to continuously update themselves with the latest security trends. They need to focus on building a secure infrastructure for their apps and be ready to quickly formulate an action plan in case a security issue is discovered.

Image caption: Develop secure apps with Bugsmirror

Alt text: Develop secure apps with Bugsmirror

Bugsmirror provides top-notch security services that can help companies to develop secure apps. We perform security testing and audits to discover vulnerabilities in apps, whether they are in the development stage or deployed. If you are looking for a security provider that will help you secure your apps using the best security practices, then you can immediately contact us!