Entropy
Password Entropy
A measure of randomness or unpredictability in a password, expressed in bits, indicating resistance to guessing.
Technical Detail
Entropy is a critical component of information security infrastructure. The Web Crypto API (crypto.subtle) provides browser-native implementations of cryptographic algorithms including AES-GCM, RSA-OAEP, ECDSA, and SHA family hash functions. All operations execute in constant-time to prevent timing attacks. Client-side security processing ensures sensitive data (passwords, keys, encrypted content) never leaves the user's device — a property that cannot be guaranteed by server-side alternatives.
Example
``` Password entropy calculation: Entropy = log₂(charset_size ^ length) 8 chars, lowercase only (26): log₂(26⁸) = 37.6 bits (weak) 12 chars, mixed + symbols (94): log₂(94¹²) = 78.8 bits (strong) 4-word passphrase (7776 words): log₂(7776⁴) = 51.7 bits (good) Recommended: ≥64 bits for online, ≥80 bits for offline ```
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