Definition
An authenticator app is software used as part of an account authentication process. A common design generates time-based one-time passwords, or TOTP codes. Other apps support push approvals or cryptographic credentials. The label alone does not identify the exact protocol or prove that a login uses multiple independent factors.
How It Works
During TOTP enrollment, the service and app share a secret, often transferred through a QR code. The app combines that secret with the current time to calculate a short-lived code, so generating codes normally does not require an internet connection. A clock mismatch can cause valid-looking codes to fail. The enrollment QR code is sensitive because another person who copies its secret may generate the same codes.
Key Considerations
Install a trusted app and secure both the device and any synchronization account. Before replacing a phone, check the supported transfer and recovery procedures rather than assuming reinstalling restores all credentials. Keep backup codes separately protected. One-time codes can still be relayed through phishing websites, so inspect the destination before entering them. Never approve an unexpected push request just to stop repeated prompts. App-based authentication protects the service account; it does not recover or replace a blockchain seed phrase.