NIST SP 800-63B Strong Password & Passphrase Generator

Our NIST SP 800-63B Compliant Strong Password & Passphrase Generator produces high-entropy credentials, memorable diceware passphrases, and secure numeric PINs powered by the browser's hardware-backed Cryptographically Secure Pseudorandom Number Generator (CSPRNG). Every character is selected locally using unbiased rejection sampling over crypto.getRandomValues(). Zero plaintext passwords, seeds, or telemetry metrics are ever transmitted across the network.

NIST SP 800-63B Guidelines & Modern Password Security

The National Institute of Standards and Technology (NIST) overhauled digital identity standards under Special Publication 800-63B, establishing:

1. Length Over Complexity: Length provides exponentially higher mathematical entropy than arbitrary character complexity.
2. No Arbitrary Expiration: Forcing 90-day password resets causes predictable human behavior.
3. Memorable Passphrases: Multi-word passphrases provide 80-100+ bits of entropy while remaining humanly typeable.

Shannon Entropy & GPU Brute-Force Time Estimation

Developer Implementation Code Snippets

Node.js & TypeScript

export function generatePassword(length = 20): string {
  const chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()-_=+';
  const buf = new Uint32Array(length);
  crypto.getRandomValues(buf);
  return Array.from(buf, n => chars[n % chars.length]).join('');
}

Python 3

import secrets, string
alphabet = string.ascii_letters + string.digits + "!@#$%^&*()-_=+"
password = ''.join(secrets.choice(alphabet) for _ in range(24))