Question 1

How do I check if my password has been in a data breach?

Accepted Answer

Enter your password into the breach checker. It uses k-anonymity via the Have I Been Pwned API � only the first 5 characters of a SHA-1 hash are transmitted, never your actual password. The API returns all breach hashes starting with those 5 characters, and your browser checks locally whether your full hash appears in the list. This is the same privacy-preserving technique used by Google Chrome and Firefox's built-in breach warnings.

Question 2

Is it safe to type my real password into this tool?

Accepted Answer

Yes. The password strength analysis runs entirely in your browser using the zxcvbn library � no data is transmitted to ShieldScope. The breach check uses k-anonymity: only the first 5 hex characters of a SHA-1 hash are sent to the Have I Been Pwned API. ShieldScope's servers receive nothing. Your actual password never leaves your device.

Question 3

What makes a password strong against cracking attacks?

Accepted Answer

A strong password must survive offline cracking, where an attacker tests billions of guesses per second against a stolen hash. Length and unpredictability matter more than visual complexity � Password123! looks complex but cracks in under a second because it follows common enterprise patterns. A 20-character random password or a 5-word passphrase with genuine entropy are far more resistant than short complex passwords.

Question 4

What is k-anonymity in password checking?

Accepted Answer

K-anonymity lets you check whether a password appears in breach databases without revealing the password itself. Your browser hashes the password with SHA-1, then sends only the first 5 characters of that 40-character hash to the Have I Been Pwned API. The API returns all breach hashes matching those 5 characters. Your browser then checks locally whether your full hash is present. The server never sees enough data to reconstruct your password.

Password Strength Checker & Data Breach Exposure Tool