bcrypt

Developer Builds Password Manager with Plausible Deniability Using Argon2id and XChaCha20-Poly1305

A Java backend developer rewrote a personal password manager originally built with Electron and React, migrating it to Tauri and Rust while redesigning its storage to support plausible deniability. The new implementation derives keys with Argon2id using a single per-install salt and encrypts files with XChaCha20-Poly1305, storing only random 32-character hex filenames without any headers or magic bytes. Multiple decoy vaults of identical size are created automatically for every user, and all files in the folder receive synchronized timestamps to eliminate metadata-based identification of the active vault. History and sync data are stored as additional encrypted files of the same format, making it impossible to distinguish real from decoy vaults from the filesystem alone. The approach mirrors VeraCrypt hidden volumes but operates on ordinary files and folders, with the explicit goal of providing deniability when a user is compelled to reveal a password.

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.

Hashcat Password Cracking: Why Complex Passwords Like Summer2026! Often Fail First

Password cracking tools such as hashcat and John the Ripper exploit predictable human patterns when generating candidates, allowing structured passwords to be recovered faster than truly random strings. The process relies on comparing computed hashes against stored values without needing to reverse the one-way function. Modern password storage uses salted, computationally expensive algorithms including bcrypt, Argon2id, sha512crypt and yescrypt to increase the cost of each guess. Different formats require specific hashcat modes, and parameters such as cost factors or memory settings directly affect cracking speed. WordPress 6.8 introduced bcrypt with SHA-384 preprocessing while older phpass records remain supported. Audits must preserve full hash records, verify modes on test data, and combine dictionaries, rules, masks and statistical models to measure real risk. After testing, organizations should migrate to properly tuned Argon2id and enforce long unique passphrases managed by password managers.

Bcrypt Password Hashing Silently Ignores Characters Beyond 72 Bytes, Breaking Verification Expectations

The bcrypt algorithm, widely used for password hashing in PHP and Python applications, processes only the first 72 bytes of any input password. Additional characters are ignored without error or warning during both hashing with password_hash and verification with password_verify. This behavior stems from the fixed 72-byte P-table size in the underlying Blowfish cipher as defined in the 1999 specification. Long passphrases, especially those using multibyte UTF-8 characters like Cyrillic or emojis, can result in completely different strings producing identical hashes. The limitation creates risks during password manager usage, system migrations, and scenarios involving shared prefixes. Modern libraries such as Python's bcrypt 4.x now explicitly reject passwords exceeding 72 bytes, while older implementations continue silent truncation. Recommended fixes include enforcing byte-length validation or pre-hashing with SHA-256 before bcrypt.