OpenSSH is a Unix/Linux port of OpenBSD, a full implementation of the SSH1 and SSH2 protocols. It includes sftp client and server support.

OpenSSH is a FREE version of the SSH protocol suite of network connectivity tools that helps increase numbers of users relying on the Internet. Most of the users of telnet, rlogin, ftp, and other such programs believe that their passwords are safe and transmitted in an encrypted form. However, they do not realize that these are transmitted without being encrypted. OpenSSH encrypts all traffic (including passwords) to effectively eliminate eavesdropping, connection hijacking, and other network-level attacks. Additionally, OpenSSH provides numerous secure tunneling capabilities, and a variety of authentication methods.

OpenSSH has originally been developed by the OpenBSD Project. The version that was first inserted into an operating system was OpenBSD 2.6.

OpenSSH is developed using code from roughly 10 countries, and is freely useable and re-useable by everyone under a BSD license.

The following are the key features of OpenSSH:
· Open Source
· Free License
· Strong Encryption with 3DES, Blowfish, AES, Arcfour etc.
· X11 Forwarding to encrypt X Window System traffic
· Port Forwarding to encrypt channels for legacy protocols
· Strong Authentication with Public Key, One-Time Password and Kerberos Authentication
· Agent Forwarding with Single-Sign-On
· Interoperability – compatible with SSH 1.3, 1.5, and 2.0 protocol Standards
· SFTP client and server support in both SSH1 and SSH2 protocols.
· Kerberos and AFS Ticket Passing
· Data Compression