🔑 Deep Dive · Intermediate

What a secure Flutter authenticator must get right

Authenticator apps are small UIs with outsized security consequences. Whether you study Aegis or another TOTP client, the Flutter-relevant lessons are the same.

Diagram: Secure Authenticator UX

Non-negotiables

  1. Secrets encrypted at rest (platform keystore/keychain when available).
  2. Screenshot/clipboard hygiene and auto-lock.
  3. Backup export that is encrypted — and tested restore.

UI notes

Large OTP lists need virtualization and urgency in copy-paste feedback. Accessibility labels should include the account name, not only the code.

Pitfalls

Storing seeds in plain SharedPreferences is how “security” apps fail reviews and user trust.

Even for a learning project, practice secure defaults.

#Flutter#OpenSource#Security