This repository is the bcrypt-ruby gem, a Ruby library implementing OpenBSD's bcrypt() password hashing algorithm. It provides a secure, computationally expensive hash for storing user passwords. The gem includes a native C extension (MRI) and a pure Java implementation (JRuby), wrapping the well-known crypt_blowfish public domain code by Solar Designer. The Ruby API is clean and minimal, exposing BCrypt::Password for creating and verifying hashes, and BCrypt::Engine for lower-level salt generation and cost calibration. The library is heavily tested, interoperable with other bcrypt implementations, and includes constant-time comparison to prevent timing attacks. It is a mature, widely-used security library with active maintenance.