The SSH protocol allows any client and server programs built to the
protocol's specifications to communicate securely and to be used
interchangeably.
Two varieties of SSH (version 1 and version 2) currently exist. SSH
version 1 makes use of several patented encryption algorithms (however,
some of these patents have expired) and is vulnerable to a well known
security exploit that allows an attacker to insert data into the
communication stream. The OpenSSH suite under Red Hat Enterprise Linux uses SSH version 2
which has an enhanced key exchange algorithm not vulnerable to the
exploit in version 1. However, the OpenSSH suite does support version 1
connections.
 | Important |
|---|
| | It is recommended that only SSH version 2-compatible servers and
clients are used whenever possible.
|
