Introduction
Fintech has revolutionized the way we manage our money. The growth in this sector has been nothing short of exponential, with digital transactions projected to reach a staggering $10.52 trillion by 2025.
With this convenience comes a major security concern: protecting the financial data. Successful transactions have no value without strong security measures in place. Breaches, phishing attacks, and unauthorized access can devastate users and businesses alike.
9 Steps to Secure Fintech App Development
Building a secure fintech app requires a multi-layered approach. The 9 crucial steps to follow are:
Step 1: Secure Coding from the Ground Up
Fintech apps necessitate robust security due to the sensitivity of financial data they handle. Here’s how to achieve this:
- Shift Left Security: Integrate security throughout the development lifecycle. This includes threat modeling, secure coding practices, and code reviews to proactively identify and fix vulnerabilities.
- Coding with Security in Mind: Utilize established secure coding practices like input validation to prevent code injection, data sanitization to eliminate hidden vulnerabilities, and strong encryption for sensitive data.
- Automated Vulnerability Detection: Regularly scan code with automated tools to uncover potential weaknesses and coding errors exploitable by attackers.
- Maintainable and Agile Code: Â Prioritize writing clean, modular, and well-documented code that facilitates future updates and vulnerability patching. This ensures agility without compromising security.
Step 2: Verifying App Authenticity
A code signing certificate acts as a digital fingerprint for your app, guaranteeing users they’re downloading a legitimate, untampered version from a trusted source. Here’s how it strengthens your fintech app’s security:
- Verifies App Origin and Integrity: During download, the app store or device checks the code signing certificate. This confirms the app originates from the declared developer and hasn’t been modified since signing.
- Mitigates Malware Deception: Malicious actors often disguise malware as legitimate apps. Code signing certificates make such deception difficult. App stores only allow signed apps, and a valid certificate indicates the app hasn’t been tampered with by a third party.
- Boosts User Trust: A valid code signing certificate instills confidence in users. They understand they’re downloading an authentic app from a reputable source, reducing the risk of malware that could steal financial data.
Obtaining a code signing certificate is a straightforward process. Certificate authorities (CAs) verify your developer identity before issuing the certificate. Choose a certificate type that aligns with your app’s needs and target audience. Some recommended types of code signing certificates and certificate authorities (CAs) you can consider:
| Types of Code Signing Certificates | Description |
|---|---|
| Standard Code Signing Certificate |
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| EV (Extended Validation) Code Signing Certificate |
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| Multi-Domain Code Signing Certificate |
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| Recommended Certificate Authorities (CAs) | Description |
|---|---|
| DigiCert |
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| GlobalSign |
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| Comodo (now Sectigo) |
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| Symantec (now NortonLifeLock) |
|
Step 3: Building a Security-First Mindset
Security shouldn’t be an afterthought. To integrate robust security principles throughout your app’s functionality, you should focus on:
- Secure Architecture: Design with security in mind. This includes separating sensitive data from the UI, implementing granular access controls, and using secure communication protocols for data transmission.
- Holistic Approach: Don’t just secure logins. Attackers exploit any weakness. Secure all aspects, from data storage to user interactions and network communication.
- Robust Infrastructure: Choose reliable cloud providers with a proven security track record. Consider Amazon Web Services’ secure environment with tools to protect against threats like DDoS attacks and data breaches.
- Continuous Secure Coding: Remember secure coding practices from Step 1? They remain essential throughout development.
Step 4: Enforce Strong Passwords
Weak passwords are a hacker’s dream. How to make them a nightmare:
- Minimum Complexity: Enforce password complexity rules. Mandate minimum length and require a combination of upper/lowercase letters, numbers, and symbols. This diversity thwarts brute-force and dictionary attacks.
- Ban Password Reuse: Disallow users from setting passwords they’ve used elsewhere. A data breach on one platform shouldn’t unlock your fintech app.
- Regular Password Rotation: Enforce mandatory password changes at set intervals to minimize the risk from stolen passwords.
- Educate Users: Promote strong password practices. Guide users on creating complex passwords and avoiding reuse. Consider recommending password managers for secure storage.
Step ​​5: Two-Factor Authentication (2FA)
Usernames and passwords, while important, aren’t foolproof. Hackers can employ various techniques to steal login credentials. Two-factor authentication (2FA) adds an extra layer of security to fortify your fintech app’s defenses. How 2FA works:
- The First Factor: What the user knows (password, PIN).
- The Second Factor: What the user has (unique code or token).
Second Factor Options:
- Time-Based One-Time Password (TOTP): Unique code generated by a smartphone app (e.g., Google Authenticator), expiring after a short time (30-60 seconds).
- SMS Verification: One-time code sent via SMS to the user’s registered phone number (Note: Less secure due to potential phone network vulnerabilities).
- Security Key: Physical hardware token that plugs into a device or connects via Bluetooth for the second factor.
Benefits of 2FA:
- Enhanced Security: Stolen passwords become useless without the second factor.
- Reduced Account Takeover: Makes it significantly harder for attackers to gain access.
- Increased User Trust: Demonstrates commitment to user security and data protection.
Step ​​6: Mobile Encryption
Data encryption is your app’s vault, protecting sensitive information. Unencrypted data is like plain text, anyone can read it if intercepted. Encryption scrambles data with a key, making it unreadable without the key. This secures both data at rest (on the device) and in transit (over networks).
In addition to encryption, adhering to security standards like PCI DSS when handling cardholder data adds an extra layer of protection.
Benefits of Mobile Encryption:
- Data at Rest Protection: Encrypted data like account numbers and transactions remain unreadable even if a hacker breaches the device.

- Data in Transit Security: Encryption shields data traveling between the user’s device and your servers, preventing anyone from deciphering it during transmission.

- Regulatory Compliance: Encryption helps meet financial regulations mandating data protection.
Choosing Encryption Algorithms:
Popular options for mobile app security include:
- Advanced Encryption Standard (AES): Widely used and highly secure, AES is a strong choice for both data at rest and in transit.

- RSA (Rivest–Shamir–Adleman): This asymmetric algorithm uses separate keys for encryption and decryption, often used for secure key exchange and digital signatures.
Step 7: A Strong Application Programming Interface (API)
Fintech apps leverage APIs to connect with backend systems. These APIs act as data bridges, but just like bridges, they need strong security measures. Here’s how to ensure secure API interactions:
API Token Management: APIs often use tokens for authentication. Think of them as digital keys granting access to specific app resources. Here’s how to manage them securely:
- Frequent Rotation: Regularly rotate tokens to minimize risk if one is compromised.
- Short Lifespans: Assign short lifespans to tokens, limiting the window of opportunity for attackers.
- Secure Storage: Store tokens securely on the server-side, not on the user’s device.
Authentication, Authorization, and Identification (AAI): Implement a robust AAI system to ensure only authorized users and applications can access specific resources:
- Authentication: Verify the identity of users or applications trying to access the API.
- Authorization: Determine the access level (read, write, etc.) granted to authenticated users or applications.
- Identification: Track and audit API access attempts to identify suspicious activity.
Secure Communication Channels: Ensure all communication between your app and the API uses secure protocols like HTTPS. HTTPS encrypts data in transit, protecting it from eavesdropping and attacks.
Regular API Monitoring: Monitor your API activity for anomalies or suspicious access attempts. This allows for prompt detection and response to potential security threats.
Step 8: Transparency
Security isn’t just about technical measures. User trust hinges on understanding how you handle their data. To build an open and trusting relationship, consider:
Crystal-Clear User Agreements: Ditch legalese! Rewrite agreements in plain language. Explain what data you collect, how it’s used, and the security measures in place.
Comprehensive Privacy Policy: Outline your data practices clearly. Explain what data is collected (personal information, device data, etc.), how it’s used (authentication, personalized services, etc.), and with whom it might be shared (if applicable).
Educate Your Users: User education is continuous. Provide informative content (tutorials, FAQs, interactive tools) on:
- Strong password practices
- Phishing scams and identification
- Secure mobile app usage tips
- The benefits of 2FA
Empowering users with knowledge makes them active participants in data security. They’ll be better equipped to identify and avoid risks, ultimately strengthening your app’s overall security.
Responsive Communication: Address user inquiries and privacy concerns promptly and transparently. Maintain open communication channels to build trust.
Step 9: Continuous Vigilance
Cybersecurity is a never-ending battle. Even with the best defenses in place, new threats constantly appear. This is why continuous vigilance is crucial for maintaining a strong security posture.
Patch Management: Software vulnerabilities are entry points for attackers. Patching them swiftly with the latest updates is critical. A defined patch management process ensures timely updates are applied to all systems.
Security Monitoring: Your network needs constant monitoring for suspicious activity, just like a fire alarm system. Security monitoring tools detect intrusions, malware infections, and other incidents so you can take swift action.
Incident Response Plan: What if a security breach occurs? Having a well-rehearsed incident response plan is essential. This plan outlines steps to contain the breach, eliminate the threat, and recover quickly. By following a documented plan, you can minimize damage and restore normalcy efficiently.
Logs provide decisive visibility into the behavior of a running app, helping to identify and resolve issues on time. Why logs matter and how to manage them effectively:
Benefits:
- Improved Debugging and Analysis: Â Logs streamline troubleshooting by providing a record of application activity. Developers can pinpoint errors and identify root causes for faster resolution.
- Strengthened Security Posture: Logs serve as a security audit trail. They record user actions, access attempts, and potential security breaches, enabling forensic analysis and threat mitigation.
- Performance Optimization: Logs offer valuable insights into app performance. By analyzing log data, you can identify areas for improvement and proactively address potential issues before they impact users.
Effective Log Management:
- Centralized Logging System:Â Implement a centralized logging system to collect logs from all app components. This simplifies log analysis and correlation of events.
- Log Retention Policies: Establish log retention policies that comply with regulations while considering storage limitations.
- Secure Log Data: Ensure logs don’t contain sensitive user information like passwords or financial data. Mask or anonymize sensitive data before storing it in logs.
Ralabs team dedicated 12 months to developing a payment middleware solution from scratch.
Conclusion
The financial data entrusted to your fintech app demands a strong security posture. By following the steps outlined above, you can create a layered defense that safeguards user information and builds trust. 

For a truly robust security posture, consider pursuing industry recognized security certifications such as SOC 2, ISO 27001, and PCI DSS. These certifications demonstrate your commitment to data security and regulatory compliance, fostering trust with users and regulators alike.

Don’t be left wondering how to implement these best practices. Contact us today and our team of security experts will guide you through every step, ensuring your app meets the highest security standards.
FAQ: Your Fintech App Security Questions Answered
The cost of developing a fintech app depends on several factors. The complexity of features, app design, desired functionality, and the development team you choose all play a role. A basic app with minimal features might cost around $30,000, while a complex app with advanced functionalities could reach $250,000 or more.
Development timelines can vary depending on the app’s complexity. A basic app could take 3-4 months to build, while a more intricate app with advanced functionalities could take a year or more.
Security is paramount when integrating third-party components. Here are some crucial considerations:
- Security Reputation: Research the third-party provider’s track record. Choose established companies with a proven commitment to data security. It’s important to select providers who take data security seriously.
- API Security Measures: Understand the security measures implemented by the third-party API. Look for features like strong authentication, encryption, and regular security audits. Before integrating any third-party API, ensure it has strong security measures in place to protect your user data.
- Data Sharing Agreements: Carefully review data sharing agreements with third-party providers. Ensure they comply with relevant data privacy regulations and outline how user data will be handled. Data sharing agreements should clearly define how user data is handled by both you and the third-party provider.
Contractual Obligations: Clearly define security expectations and responsibilities in your contracts with third-party providers. Clearly defined contracts help ensure that both you and the third-party provider are on the same page regarding security expectations.
If a security incident or data breach occurs, a swift and decisive response is critical. Here’s how to approach the situation:
- Immediate Response: Act quickly to contain the breach and prevent further damage. Isolate the affected systems and identify the root cause of the incident. Your first priority should be to stop the breach from spreading and to identify how it happened.
- User Notification: Transparency is key. Inform users about the breach in a timely manner, explaining what data was compromised and the steps you’re taking to address the issue. Be transparent with your users about the breach and the steps you’re taking to fix it.
- Regulatory Reporting: Depending on the nature and severity of the breach, you may be required to report it to relevant regulatory bodies. Depending on the regulations in your area, you might need to report the breach to the appropriate authorities.
Investigation and Remediation: Conduct a thorough investigation to understand how the breach occurred and implement corrective measures to prevent similar incidents in the future. Investigate the breach thoroughly to understand how it happened and take steps to prevent similar incidents from happening again.
