Secure Shell (SSH) is a means of connecting to systems using a client-server model with very high levels of security. It relies on users exchanging encrypted keys with each other to prove their identity in such a way that even if keys are intercepted, no one else can use them. All data traffic is encrypted for a session between client and server, including the user id and password. This differs from SMB, Telnet or FTP where user IDs and passwords are sent in clear text.
The encryption afforded by SSH has been packaged into a number of commercial offerings.
It is also available in a selection of Open Source forms such as OpenSSH for Windows, and is often delivered as a native facility with many operating systems.
Secure Shell comes with a number of features including a command-line, similar to Telnet, and a Secure FTP capability. Many other connectivity features exist with SSH but it is only these two that Syncsort™ Capacity Management uses.
SSH can authenticate to a target system either by using a password, or purely by public key. Syncsort™ Capacity Management supports both methods. Syncsort™ Capacity Management securely stores passwords in an encrypted form. SSH has two versions, SSH1 and SSH2. SSH2 enhanced many of the facilities of the original SSH1, but unfortunately relies on keys that have a different format to those used by version 1. Most newer implementations of SSH support both SSH1 and SSH2, but you need to ensure both ends of the SSH conversation are configured to talk to each other correctly using matching SSH versions. If you are mixing SSH1 and SSH2 you will probably have to manually convert the keys of one side of the session to the other type before connectivity will work, but it is beyond the scope of this document to describe how to do this, given the wide variety of software available.