What security concerns matter in a React Native app?

A mobile app ships its code to users, so anything embedded in the bundle can be extracted. Security therefore depends on keeping secrets server-side, minimising what the client knows, and protecting the transport and local storage of sensitive data.

The essentials

• Store tokens and keys in Keychain or Keystore-backed storage, not AsyncStorage
• Use TLS everywhere and consider certificate pinning for high-risk APIs
• Never embed API secrets, private keys or admin credentials in the bundle
• Validate every deep link and WebView URL against an allowlist
• Clear sensitive data on logout and avoid logging tokens or personal data
• Disable text selection or screenshots for highly sensitive screens where appropriate

import * as SecureStore from "expo-secure-store";

export async function saveSession(token: string) {
  await SecureStore.setItemAsync("session", token, {
    keychainAccessible: SecureStore.WHEN_UNLOCKED_THIS_DEVICE_ONLY,
  });
}

export async function clearSession() {
  await SecureStore.deleteItemAsync("session");
}

Certificate pinning raises the bar but adds operational risk: rotating a certificate without updating the app can break every user. Use it only with a rotation plan and backup pins. Jailbreak and root detection can be bypassed, so use them as signals rather than as the only control.