Password Strength Checker

Security is not about complexity; it is about entropy. A short string of random characters often outperforms a long string of predictable dictionary words. This utility employs a multi-vector analysis engine to evaluate password resilience. Unlike basic checkers that count characters, this tool analyzes Information Entropy (measured in bits), detects common keyboard patterns (e.g., "qwerty"), and penalizes repetitive substrings.

Crucially, this tool implements the k-Anonymity protocol for breach detection. When you type a password, the browser calculates its SHA-1 hash locally. Only the first 5 characters of that hash are sent to the standard breach database API. The API returns a list of suffixes, and your browser performs the final match locally. Your full password never leaves the client environment, ensuring mathematical privacy while cross-referencing against over 600,000,000 exposed credentials.

The core metric is Information Entropy (H), which measures the unpredictability of the password. The search space (S) is determined by the character set size (N) raised to the power of the length (L).

However, real-world entropy must account for patterns. We apply a penalty factor (P) for consecutive sequences (e.g., "123", "abc") or dictionary words.

Time to crack (t) is estimated based on an offline GPU cluster capable of 100 Gigahashes per second (R).