Mobile App Security Best Practices for 2025: Lessons from Finance Apps
Explore essential security measures every mobile app should implement, based on industry-leading standards from financial applications.
In 2024 alone, mobile app data breaches exposed over 1.5 billion user records. As we move into 2025, security isn't just a feature—it's a fundamental requirement. Finance apps, which handle the most sensitive user data, have pioneered security practices that every app developer should adopt.
Why Mobile Security Matters More Than Ever
Your users trust you with their data. Whether it's financial records, personal photos, or health information, a single breach can destroy that trust permanently. The consequences extend beyond reputation:
Average cost of a data breach (IBM 2024)
Users who abandon apps after a breach
Average time to identify a breach
Essential Security Measures for Mobile Apps
1. Biometric Authentication
Passwords are the weakest link in mobile security. Biometric authentication—fingerprint and Face ID—provides stronger security with better user experience.
Implementation Tips:
- ✅ Use platform-native biometric APIs (LocalAuthentication on iOS, BiometricPrompt on Android)
- ✅ Always provide a fallback PIN/password option
- ✅ Store biometric keys in secure enclave/keystore
- ✅ Re-authenticate for sensitive operations
2. End-to-End Data Encryption
Encrypt data at rest and in transit. Even if attackers gain access to storage, encrypted data remains unreadable without the keys.
Encryption Standards:
- ✅ AES-256 for data at rest
- ✅ TLS 1.3 for data in transit
- ✅ Hardware-backed key storage
- ✅ Unique encryption keys per user/device
3. Secure Local Storage
Never store sensitive data in plain text. Use platform-provided secure storage mechanisms designed for sensitive information.
Secure Storage Options:
- ✅ iOS Keychain for credentials and tokens
- ✅ Android EncryptedSharedPreferences
- ✅ SQLCipher for encrypted databases
- ✅ Never store secrets in code or config files
4. Offline-First Security
The most secure data is data that never leaves the device. Offline-first apps like FineMe eliminate entire categories of attack vectors by keeping sensitive data local.
Why Offline-First is More Secure:
- ✅ No server = no server breach
- ✅ No network transmission = no interception
- ✅ User controls their own data completely
- ✅ Eliminates man-in-the-middle attacks
Advanced Security Measures
🛡️ Certificate Pinning
Pin your server's SSL certificate to prevent man-in-the-middle attacks, even if a root CA is compromised.
🔍 Root/Jailbreak Detection
Detect compromised devices and warn users or restrict sensitive functionality on rooted/jailbroken devices.
🔄 Secure Backup
Encrypt backups with user-controlled passwords. Never store backup encryption keys on servers.
⏱️ Session Management
Implement automatic session timeouts and require re-authentication after periods of inactivity.
Case Study: How FineMe Implements Bank-Grade Security
FineMe, our personal finance manager, implements all the security best practices discussed above:
Fingerprint & Face ID authentication required to access the app
Financial data never leaves your device—no servers to breach
Password-protected local backups with AES encryption
Zero personal data collection—not even an email address
Mobile App Security Checklist for 2025
Authentication
- ☐ Biometric authentication implemented
- ☐ Secure fallback authentication
- ☐ Session timeout configured
- ☐ Re-auth for sensitive actions
Data Protection
- ☐ Data encrypted at rest (AES-256)
- ☐ Data encrypted in transit (TLS 1.3)
- ☐ Secure storage for sensitive data
- ☐ No hardcoded secrets in code
Network Security
- ☐ Certificate pinning enabled
- ☐ Secure API endpoints only
- ☐ Request signing implemented
- ☐ Rate limiting on server
Code Security
- ☐ Code obfuscation enabled
- ☐ Root/jailbreak detection
- ☐ Debugger detection
- ☐ Integrity verification
Building Trust Through Security
In 2025, users are more security-conscious than ever. They're reading privacy policies, checking data safety sections on app stores, and choosing apps that respect their privacy. The apps that thrive will be those that make security a core feature, not an afterthought.
Whether you're building a finance app, a health tracker, or a social platform, the security lessons from financial applications apply universally. Start with biometric authentication, encrypt everything, minimize data collection, and whenever possible, keep sensitive data offline. Your users—and your business—will thank you.