High Quality Content by WIKIPEDIA articles! BSD Authentication, otherwise known as BSD Auth, is an authentication framework and software API employed by some Unix-like operating systems, specifically OpenBSD and BSD/OS, and accompanying system and application software such as OpenSSH and Apache. It originated with BSD/OS and although the specification and implementation were donated to the FreeBSD project by BSDi, ultimately OpenBSD chose to adopt the framework in release 2.9. Pluggable Authentication Modules (PAM) serves a similar purpose on other operating systems such as Linux, FreeBSD and NetBSD.