Password Generator — Cryptographically Random Passwords That Cannot Be Guessed or Cracked

Human-chosen passwords are predictable in ways that automated password crackers systematically exploit. People choose dictionary words, names of pets and family members, significant dates, and keyboard patterns (qwerty, 123456) because these are memorable. They add numbers and special characters at the ends or substitute visually similar characters (@ for a, 3 for e, 0 for o) because they were told to include them. These substitution patterns are in every password cracking dictionary. A password that feels complex because it contains a capital letter, numbers, and a special character — Password1! — falls to an automated attack within seconds because the pattern is known. True password strength comes from randomness that has no pattern, not from complexity rules applied to memorable words.

Entropy — measured in bits — is the correct metric for password strength, not character count alone. A 12-character password composed of truly random lowercase letters has log₂(26¹²) = 56.6 bits of entropy. A 12-character password using all 94 printable ASCII characters has log₂(94¹²) = 78.8 bits. Adding uppercase, numbers, and symbols to a 12-character password increases entropy by 22 bits — equivalent to making a lowercase-only password 7.4 characters longer. For context, modern password cracking hardware can attempt 100 billion MD5 hashes per second — a 56-bit entropy password has a 50% chance of being cracked in 365 days of sustained attack. A 78-bit entropy password requires 80,000 years at the same attack rate. The generator produces passwords at configurable entropy levels with the bit entropy displayed so the strength is a quantitative fact, not a color-coded approximation.

Passphrase generation — producing passwords as sequences of random common words rather than random characters — addresses the memorability problem without sacrificing cryptographic strength. A four-word passphrase randomly selected from a 7,776-word list (the EFF long wordlist) has log₂(7776⁴) = 51.7 bits of entropy. A five-word passphrase has 64.6 bits. "correct horse battery staple" is both memorable — four concrete nouns that form a mental image — and cryptographically stronger than most character-based passwords people actually use. The generator produces both character-based passwords for systems that require specific complexity rules and wordlist-based passphrases for systems that accept long passwords and benefit from human memorability.