The #1 Mistake Developers Make with Payment Data — and How to Fix It

APIs and payment tokens are the real attack surface in 2025 — not your UI.

If your backend or client leaks secrets, attackers don’t need to hack your app… they just walk through your API. 🚪

Here’s the most common developer mistake 👇

🧨 Storing payment tokens in SharedPreferences (plaintext, rootable, and non-compliant).

✅ The fix?

Use Android Keystore + AES/GCM to encrypt and protect secrets with biometric/PIN authentication.

💡 Bonus:

• Use EncryptedSharedPreferences for ciphertext
• Rotate keys on logout
• Don’t log decrypted data
• Require auth via setUserAuthenticationRequired(true)

🔗 Read the full breakdown and Kotlin 2025 code here:

The #1 Mistake Developers Make with Payment Data — and How to Fix It