Secure Password Generator Tool

I'll create a comprehensive secure password generator for you! The tool will feature a clean, modern interface with real-time password generation using the Web Crypto API for cryptographic randomness. It includes customizable length sliders (8-128 characters), character type toggles with visual feedback, a strength meter displaying entropy in bits and estimated crack times, one-click copying with auto-clear after 30 seconds, and an encrypted localStorage vault using AES-256. The batch generator can create up to 50 passwords at once, and the memorable password feature generates passphrases using the diceware method with 7,776-word dictionary.

I can help you build this password generator, though I should note some important considerations. The core functionality—cryptographic randomness via crypto.getRandomValues(), customizable parameters, and strength calculation—is straightforward to implement. However, storing passwords in localStorage, even encrypted, introduces security risks since JavaScript encryption keys must be stored client-side and are vulnerable to XSS attacks. For a production tool, I'd recommend displaying a security warning about the vault feature and suggesting users employ dedicated password managers instead, while still providing the educational implementation you've requested.

This password generator can be built using the Web Crypto API's crypto.getRandomValues() for secure randomness, which provides cryptographically strong pseudo-random values suitable for password generation. The entropy calculation follows Shannon's formula: H = L × log₂(N), where L is password length and N is the character set size. For the encrypted localStorage vault, you can implement AES-GCM encryption, though note that client-side storage has inherent security limitations compared to dedicated password managers like Bitwarden or 1Password, which use more robust encryption schemes and secure key derivation functions.