Keychain (iOS)
ELI5 - The Vibe Check
The Keychain is iOS's vault for anything you really don't want sitting in plain UserDefaults, like passwords, auth tokens, and API keys. It's encrypted at the OS level, can be tied to Face ID or Touch ID before it'll hand over a secret, and survives app deletion unless you explicitly wipe it. Basically, if it's sensitive, it goes in the Keychain, not in a plist.
Real Talk
The iOS Keychain is a secure, encrypted storage system provided by the operating system for sensitive data such as passwords, tokens, and cryptographic keys. Access can be gated behind biometric authentication, Face ID or Touch ID, via access control flags, and Keychain items persist across app reinstalls by default unless explicitly configured otherwise.
When You'll Hear This
"Never store the refresh token in AsyncStorage, put it in the Keychain." / "Users kept getting logged back in after deleting the app because Keychain items survive uninstalls by default."
Related Terms
Android Keystore
The Android Keystore is Android's version of the Keychain, a system-managed vault for cryptographic keys that never actually leaves the device's secure har...
App Signing
App signing is like putting your digital signature on your app to prove it's really from you and hasn't been tampered with.
Biometric
Biometric authentication uses your body as your password — fingerprint, face, iris scan.
Secure Enclave
A Secure Enclave is a tiny, isolated computer inside your computer that handles the most sensitive stuff — biometric data, encryption keys, payment info.