ELI5: What are Push Notifications for Authentication?

Push notifications send a message to your phone asking you to approve a login. You just tap yes or no — it is faster and safer than typing in a code.

Definition

Push notification-based MFA is an authentication method where, after a user enters their password, the authentication system sends a push notification to the user’s registered mobile device. The user reviews the notification details and taps Approve or Deny to complete or reject the authentication attempt. This provides a user-friendly MFA experience without requiring users to manually enter OTP codes.

Key Details

  • More user-friendly than TOTP: no code to copy; one-tap approval
  • Modern push notifications should include context: application name, location, IP address of login attempt
  • Vulnerable to MFA fatigue attacks (push bombing) — mitigated by number matching and location-based verification
  • Requires internet connectivity on the user’s mobile device to receive push notifications
  • Number matching (showing a code in the login page that must match the code in the push) defeats MFA fatigue attacks

Connections