FreeBSD Handbook Prev Chapter 8. Security Next 8.10.
Secure shell is a set of network connectivity tools used to access remote machines securely.
It can be used as a direct replacement for rlogin , rsh , rcp , and telnet . OpenSSH is maintained by the OpenBSD project, and is based upon SSH v1.2.12 with all the recent bug fixes and updates. It is compatible with both SSH protocols 1 and 2. OpenSSH has been in the base system since FreeBSD 4.0. 8.10.1. OpenSSH offers a variety of authentication and encryption methods to prevent this from happening.