PassShield wót Libor Benes (Dr. B)

PassShield is a lightweight Firefox sidebar extension providing secure, fully offline password generation and encrypted local storage. All processing occurs client-side — no telemetry, no network requests, no data collection of any kind.

The extension combines a cryptographically secure password generator with an AES-GCM encrypted vault. Users can customize password length (16-50 characters) and character sets, with real-time strength feedback. Generated passwords can be instantly copied or saved to the vault with descriptive labels and timestamps (date, time).

The vault employs industry-standard encryption: PBKDF2 with 600,000 iterations for key derivation, AES-GCM 256-bit for authenticated encryption. Master passwords are never stored — only used to derive encryption keys. Make sure you store your masteer password in a safe place, it cannot be recovered. Each saved password is automatically timestamped, making duplicates easily distinguishable and providing clear version history.

Vault features include searchable entries, one-click copy/show/delete operations, and complete export/import of encrypted backups with metadata preservation. Users can change their master password (automatically re-encrypting all entries), reset the vault completely, or lock it when stepping away.

PassShield embodies a security-first philosophy: no unsafe code, no third-party libraries, and no remote resources. Every operation uses safe DOM methods and validated inputs. The extension requests only essential permissions (storage and clipboardWrite) and explicitly declares zero data collection in its manifest.

Target audiences include privacy-conscious users avoiding cloud services, everyday users seeking better password hygiene, developers and security enthusiasts, IT professionals, and anyone concerned about data collection and telemetry. The extension works entirely offline — no internet connection required, no data ever leaves the device.

Security-First Architecture:
• No data collection or transmission.
• All encryption local with Web Crypto API.
• Master password never stored.
• 600,000 PBKDF2 iterations.
• AES-GCM 256-bit authenticated encryption.
• Cryptographically secure random generation.
• Safe DOM manipulation (no innerHTML).
• Input validation on all user inputs.
• Zero third-party dependencies.
• No network permissions requested.

Generator Features:
• 16-50 character passwords.
• Toggle uppercase, lowercase, numbers, symbols.
• Real-time strength meter (Weak, Fair, Good, Excellent).
• One-click copy to clipboard.
• Save to encrypted vault with custom labels.

Vault Features:
• AES-GCM encrypted storage.
• Automatic timestamping of all entries.
• Smart dynamic search by label.
• Show/hide password visibility.
• Copy to clipboard.
• Delete individual entries.
• Export encrypted JSON backups (with metadata).
• Import previously exported vaults.
• Change master password (re-encrypts all entries).
• Reset vault (complete erasure).
• Lock/unlock functionality.

Design:
• Modern neon theme.
• Terminal-inspired color scheme.
• Compact sidebar-optimized layout.
• Clear visual hierarchy.
• Timestamps in distinctive color.

Technical Specifications:
• Compatibility: Firefox 140.0+ (64-bit desktop).
• Runtime Execution RAM Footprint: ~37 KB (manifest.json + sidebar.html + script.js).
• Total Extension Download/Install Size: ~82 KB (including README.md).
• Web Crypto API for all cryptographic operations.
• browser.storage.local for encrypted data.
• No network dependencies.
• Verified on current Firefox versions.

PassShield delivers enterprise-grade password security in a lightweight, privacy-focused package — because your passwords should stay where they belong: with you.