khadinakbarlabs/expo-mobile-app-builder/add-expo-secure-store-keystore

Add Expo Secure Store (Android Keystore)

Hardware-backed encrypted key-value store. Uses Android Keystore on Android.

Install

npm exec --no -- expo install expo-secure-store

Basic use

import * as SecureStore from 'expo-secure-store';
await SecureStore.setItemAsync('auth_token', 'jwt...');
const token = await SecureStore.getItemAsync('auth_token');
await SecureStore.deleteItemAsync('auth_token');

Android-specific options

// Require biometric or PIN to access (Android 6+)
await SecureStore.setItemAsync('sensitive', 'value', {
  requireAuthentication: true,
  authenticationPrompt: 'Verify to unlock',
});

What it uses under the hood

• Android: EncryptedSharedPreferences + Android Keystore (hardware-backed on TEE/StrongBox devices)
• Each key encrypted with hardware-derived key
• Survives app data clear (but NOT uninstall)

When NOT to use SecureStore

• Large data (use SQLite encrypted instead)
• Frequently-read values (slow ~5-10ms per read)
• Data that should survive uninstall (use cloud sync)

When to use

• Auth tokens (access, refresh)
• API keys for the user's session
• Encryption keys for local SQLite
• Sensitive user inputs (PIN, recovery phrase)

Gotcha: rooted devices

SecureStore relies on Android Keystore. On rooted devices, Keystore can be bypassed. For high-value apps, also implement:

• add-app-attestation (Play Integrity API)
• Server-side validation

Pair with

• add-supabase-auth-android for token persistence
• Use MMKV (add-zustand persistence) for non-sensitive data