Android Keystore and iOS Keychain

The Android Keystore and the iOS Keychain are the platform-provided places to store keys and sensitive data securely on a device. They are backed by the operating system and, on many devices, by dedicated hardware, which makes the stored values much harder to extract.

The common mistake is keeping tokens, keys or personal data in plain files or shared preferences instead. Using the keystore or keychain, with the right protection level, is the expected way to hold anything sensitive on the phone.