What Is a Password Manager?

The average internet user has 100+ accounts. No human can remember 100 unique strong passwords, so people reuse the same one across sites — and when any single site is breached, attackers credential-stuff that password into every other service. This is how the overwhelming majority of account takeovers happen.

A password manager solves the underlying problem by removing the need to remember. Generate a unique 20-character random password for every account, store it in an encrypted vault, autofill on demand. You memorize one master password; the vault remembers the rest.

You set a master password when you sign up. The manager derives a vault key from it using a key-derivation function (Argon2id in PassCryp's case) and encrypts your vault with AES-256-GCM. Only ciphertext is ever sent to the server. To unlock on a new device, you enter your master password — the key is re-derived locally and decrypts the synced vault.

When you visit a login form, the browser extension matches the domain against vault items and offers to fill. When you sign up for a new account, the extension offers to generate a strong password and save it. Two-factor codes (TOTP) live alongside passwords so logins stay a single, fast flow.

Zero-knowledge architecture — the provider cannot decrypt your vault. Modern key derivation (Argon2id) — not legacy PBKDF2. Authenticated encryption (AES-256-GCM) — not just AES-CBC. A browser extension you can audit (open source is best). Cross-device sync. TOTP built in. Encrypted import/export so you're never locked in.

Avoid: managers that store your master password hash on the server in a reversible way, managers without a published security whitepaper, and managers that charge extra for cross-device sync (a 2026 baseline, not a premium feature).