flutter_secure_storage – Secure Key-Value Storage in Flutter

 

🔐 flutter_secure_storage – Secure Key-Value Storage in Flutter

📘 Introduction

When developing Flutter applications, securely storing sensitive data such as access tokens, login credentials, and user preferences is critical. The flutter_secure_storage package makes this easy by providing encrypted key-value storage using platform-specific solutions:

• Android: Uses EncryptedSharedPreferences or the Android Keystore
  
  

• iOS: Utilizes the Keychain
  
  

• macOS/Linux/Web: May support secure methods or throw an error if not available
  
  

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🚀 Why Choose flutter_secure_storage?

• 🔒 Encrypted at Rest – Your data is safely stored using secure native mechanisms
  
  

• ✅ Simple API – Designed with async/await for smooth integration
  
  

• 🌍 Cross-Platform – One API for all supported platforms
  
  

• 🛡️ Ideal for Sensitive Data – Perfect for storing tokens, session keys, credentials
  
  

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🛠️ Step-by-Step Integration

1️⃣ Add the Dependency

yaml

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dependencies:

  flutter_secure_storage: ^9.0.0

📌 Always check pub.dev for the latest version.

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2️⃣ Import the Package

dart

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import 'package:flutter_secure_storage/flutter_secure_storage.dart';

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3️⃣ Initialize the Storage

dart

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final storage = FlutterSecureStorage();

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4️⃣ Basic Usage

dart

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// Save a value securely

await storage.write(key: 'token', value: '123456');

// Retrieve the value

String? token = await storage.read(key: 'token');

// Delete the value

await storage.delete(key: 'token');

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💡 Pro Tips

• Use meaningful key names like 'auth_token', 'user_email' for clarity.
  
  

• Combine with biometrics (via local_auth) for added security.
  
  

• Always use try-catch to handle platform-specific exceptions gracefully.
  
  

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🧪 How to Test Secure Storage

When writing unit tests, avoid calling native APIs directly. Instead:

• Mock FlutterSecureStorage using libraries like mockito
  
  

• Or create an in-memory substitute for testing logic without platform dependency
  
  

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🧩 Conclusion

If you're serious about protecting your users' data, flutter_secure_storage is a must-have in your Flutter toolbox. It ensures that sensitive information remains encrypted and inaccessible to unauthorized access while keeping your implementation straightforward and clean.

Secure code = Trusted apps. 🔐✨