Argon2

Passphrases vs. Leetspeak Passwords: Why Four Random Words Outperform P@ssw0rd!2026

The article explains why a passphrase made of four randomly selected words provides far greater resistance to offline attacks than a complex-looking password constructed with substitutions and appended symbols. It details how password strength is measured in bits of entropy rather than visual complexity, showing that four words drawn from a 50,000-word list yield approximately 62 bits while common leetspeak transformations add almost none. The piece contrasts fast legacy hashing with modern slow algorithms such as Argon2 and emphasizes the protective effect of per-password salting. It criticizes registration forms that reward predictable patterns and highlights NIST guidance favoring length over mandatory character rotation. The author recommends diceware-style generation for master passwords and password managers for everything else, noting that passkeys ultimately eliminate the need for memorizable secrets altogether.

Hash Functions Part 1: Core Properties, Security Requirements and Practical Applications

The article provides a detailed introduction to hash functions, explaining how they map arbitrary-length input to fixed-length output while satisfying three fundamental security properties. It covers preimage resistance, second preimage resistance, and collision resistance, along with the avalanche effect that makes even minor input changes produce unrecognizable output. The text explains why a 256-bit digest is required to achieve 128-bit collision resistance, referencing the birthday paradox and its implications for MD5 and SHA-1. Practical guidance includes using OpenSSL for hashing, applying hashes in commitment schemes, enforcing subresource integrity on web pages, and securely storing passwords with Argon2 and bcrypt. The post emphasizes that hash functions alone do not guarantee integrity without proper transmission of the digest and announces a follow-up on SHA-2 and SHA-3 internals.