SSH
Secure Shell is a telnet replacement. Telnet transmits data, including passwords, over the network unencrypted. SSH provides end to end encryption of all traffic.
Other programs that transmit data unencrypted are rsh, rcp and FTP. SSH replaces all these programs with a secure alternative. Many institutions worldwide have banned Telnet and FTP.
Downloading SSH
Unix
Most modern versions of Unix already come with ssh. SSH replaces Telnet and rsh. SCP replaces rcp. SFTP replaces FTP.
Windows
Putty is available on the internet for free as are the companion programs pscp, psftp, and pagent. A free graphical front end to pscp, WinSCP provides a drag and drop file explorer interface.
There are commercial versions of SSH, SSH server and graphical SCP client at http://www.ssh.com
Macintosh
MacOS X comes with ssh. Jaguar or better have SCP built into the Finder.
Key Management
Unix users will need to generate their ssh keys using ssh-keygen commands:
ssh-keygen -t rsa
ssh-keygen -t dsa
Using SSH
You need to know your username, password, and hostname of the server you are connecting to.
On Unix: ssh username@hostname.ics.mq.edu.au
To copy a file to a remote machine:
SCP /path/to/local/file username@hostname.ics.mq.edu.au:/path/to/remote/file
Unix and X11 Windows users should read the key management tutorial at http://www-106.ibm.com/developerworks/linux/library/l-keyc.html. SSH has many features including remote command execution, tunnelling and X11 port forwarding. See http://www.openssh.org/ for more information.