12 Crucial Steps to Build a Secure Fintech Application

5 Sep 2022 | Mobile App Development


Without a doubt, Fintech is the industry in which users expect the highest level of personal information safety. So, if you are building a Fintech mobile application for your company or clients, security should be one of the main features of your app.

Whether you are a startup looking to build a mobile app for your Fintech company or a developer who wants to create a new app, excellent security strategies are necessary for any Fintech application.

This article is for you if you need tips to strengthen your knowledge to secure your Fintech app. Today, we will discuss the five steps for developing a secure Fintech application. So, let’s get started.

Security risks for a Fintech application

Before we focus on how to secure your Fintech application, it is crucial to check the vulnerabilities of mobile applications. The list is not exhaustive, but they’re sufficient to show why you should develop high-security measures for your app. So, here are some of the security risks of a typical Fintech application.

Broken Access Control

When your application has a weak access mechanism, it can lead to broken access control, allowing hackers or users to gain unauthorised access and privileges that may cause harm to your data.

Sensitive Data Exposure

This vulnerability happens when you do not apply strong measures to protect your data in transit or at rest. What is often at risk includes passwords, credit card information, and other personal data.

Injection vulnerabilities

This risk has been typical with web attacks like XSS, LFI, and SQL Injection. However, your app is also at risk if an attacker injects a threat through your application. Injected threats will run alongside your codes, which may be to execute an access or control privilege to your data.

Insecure application design

Countless application weaknesses frequently result from weak or missing security controls. Fintech apps need to include strong and effective security controls to wade off unwelcomed application threats.

Vulnerable and outdated components

It includes any vulnerability that results from outdated or ineffective features of your apps, which are often gateways to gaining unauthorised access to your data.

Broken authentications

This vulnerability happens when there are failures in identification, authentication, and authorization. Attacks to this vulnerability exploit the systems managing the user identities, like passwords, databases, and session management.

Security logging and monitoring Failures

Logging and monitoring are critical security features for any Fintech app. When your app cannot correctly log and monitor its app performance or fail to follow the best practices, it will be difficult for it to detect and respond to security risks, which can be potentially malicious to your data.

API security risks

Several vulnerabilities come with how your app communicates with other apps and services through the APIs. While APIs are indispensable nowadays, they can expose your apps to attacks and vulnerabilities worth exploring before building your Fintech application.

How to build a secure Fintech mobile application

As we said, security in Fintech apps demands much attention. Fintech companies and banks are constantly handling sensitive data. Therefore, they have to comply with strict data security protocols.

These protocols are forcing many Fintech companies to look for better ways to enhance their security measures to adhere to such security policies and avoid the crippling impact of a data breach.

So, here are the five steps to secure your Fintech application today:

Put security at the top of your development goals and objectives.

If you start your plans to develop and maintain an application with security as your top priority, you will get a more reliable Fintech application that your users can trust.

Putting security at the top of your goals will shape every aspect of your app. Every feature of your apps or MVPs will reflect your goals, from your preferred development approaches to app interaction with third-party apps and services.

To ensure an excellent strategy for securing your Fintech app, do a thorough risk assessment of your app. A review of the possible risks will equip you with an accurate picture of your app’s security needs you should implement. Therefore, when you write your goals, your objectives should be to apply security measures you found out in your risk assessments.

Here is a process you need to be aware of when defining the goals and objectives of your app’s security:

Enforce the best coding practices to write highly secure codes

Writing secure code is one of the most vital steps in creating a powerful Fintech application. But what does it mean to write such codes? Does it mean writing your app code with security in mind, trying to keep the vulnerabilities of your app to the minimum?

Sure, that’s it, so let’s check out some best practices for keeping clean code that does not give attackers the chance to access your data.

Do not hard-code login credentials to the application code.

Hard coding login credentials is an easy way to give your logins to attackers. Sometimes, developers can try to hard-code the credentials to their code to save development time, but this often leads to security issues. Therefore, do not include any sensitive information in your code!

Strengthen your user authentication and identification

Common attacks like brute force or dictionary attacks are simple ways hackers may use to break your users’ passwords. Because most of these attacks use several combinations of passwords to gain access, limiting the number of login attempts in your code or enforcing strong passwords during signups is an effective strategy to prevent such attacks.

Randomize your session IDs

When users log in to your Fintech application, their sessions are stored locally with session IDs to let them stay logged in for some time without having to log in. These session IDs should be unique and not predictable, as attackers may use them to hijack your user’s sessions to access their accounts.

Validate all your user’s input

Checking what the user enters as an input field on your app and at the receiving end before execution is a brilliant security measure you should adopt when creating your app. Therefore, ensure that all the user inputs are valid and recheck them when received on your server.

Control the error messages that the app user can see

When some functionality fails or does not work as expected, many developers will return the system’s default error messages to the users. And these messages may carry much important information to potential hackers! So, always try to interpret your application’s error messages without exposing too much information to hackers.

Use robust testing strategies to minimize vulnerabilities.

A robust Fintech app testing is an application testing method effective for finding and eliminating vulnerabilities in Fintech applications. It involves rapid testing, analysis, and reporting on your app’s security stance throughout the software development lifecycle (SDLC).

Writing code and implementing the best code standards and practices will improve your app’s security, but how will you measure its effectiveness if you do not test your codes rigorously? You need to develop a strategy that will provide vigorous testing and in-depth security analysis of your app’s features before releasing it to the market.

If you do this testing right, you will have a more robust app with secure source codes. You will also have a powerful app that can withstand internal and external threats, giving you greater visibility of your application’s security issues.

Adopt the tools and techniques that help you identify and resolve many known software vulnerabilities. As technology advances, testing and applying strategies to improve your testing capabilities is more accessible.

The app development process has become considerably shorter, so you should see ways to balance the development speed with your testing strategies.

The Three Types of Application Security Testing

Three main types of security testing are often viable for any Fintech application. The types of pen testing that are viable for a Fintech app include:

White Box Security Testing

White box security testing is a popular type of pen testing where you share all the internals of your app, including full access to codes, credentials, and any other resources that a tester or a testing system requires. Therefore, a tester will identify vulnerabilities in your app’s business logic, code quality, misconfiguration, and other coding practices that couldn’t be possible without full access. While this method is powerful, it has drawbacks, as not these vulnerabilities are not regularly exploitable in production.

Gray Box Security Testing

Perfect for accessing the level of access for a privileged user, the gray box testing is where you provide limited access for your Fintech application. If you ask yourself how a user with some information like an account can impact the security of your app, then this is what the gray box testing will answer. This type of testing is highly efficient for your Fintech application, and you should try it, as it is a balance between the three types.

Black Box Security Testing

Whereas the gray and white box testing types involve access to some information about your application, a tester in a black box test does not have access to the internals of your app. This type is dominant for testing the impact of outside attackers on your Fintech app. Can someone who does not have any information about the app still intrude? This question is what this testing type tries to answer. It is highly worthwhile but inefficient to ensure all-around application security.

Implement a robust system for identification, authentication, and authorization

Your system of identification, authentication, and authorization is a critical aspect of security in your app. How you login to your users to use your services can break or make your app’s level of access. It is crucial to have a solid plan for allowing users to have the proper access privileges for their accounts.

If these three terms are confusing, here’s a brief definition of each one:


When a user opens your app, it does not know who it is. In trying to figure out who it could be, the system may ask for a username, an email, or consult the session storage. Therefore, your app will need to have a good process of identifying your users before moving to the next steps.


When your app knows the user, it may be necessary to prove if it is indeed the user is the person they claim to be. You may request a password, an RSA token, or bio-based info to verify that the user is whom they claim. Verification is a crucial step that you need to take seriously. There are too many cases of impersonations that you do not want to happen with your app.


The last access control step is determining when your users can access your app. What are they able to see? What can they add, remove, or change in your system? These are the questions that authorization will answer. When you do not do it right, including the other steps above, you will leave your app vulnerable to data theft, fraud, and damage to your reputation.

While all these steps are common and almost mandatory for all Fintech applications, it forms the core of security and what many people know to entail everything about it. The entrance of your app is on your authentication system; if it is weak, attackers can easily break into it. That is why gray and black pen test types often check vulnerabilities from this point before moving to other possible vulnerable entry points for your application.

What the future holds for the security of Fintech apps

There is a big market for Fintech applications. By 2026, Fintech apps are expected to grow at 13.7% CAGR to reach $190 billion by 2026, according to a new report by Research and Market. This growth rate is faster than many other industries, with growth rates of about 4%.

It is easy to celebrate and think that you can instantly pull in with the share of this growth, but it will be pointless if your app’s security is average. In 2017, Equifax suffered the most significant security breach of about 150 million users in just a few months, leading to over $4 billion in costs!

That figure can invoke some fears, and overlooking some simple security measures for your Fintech app can be disastrous. So, as you look forward to a ripe future of Fintech applications, don’t forget to equip it with strong security measures so that when success finds you, failure shouldn’t be the next!

Before you click off, we’ve got to assure you that at Aveo Software, we will not just build top-notch applications for you. If we create a Fintech app for you, we will take security seriously — so you will always stay confident when your app is finally ready for the market.