The SSH protocol allows any client and server programs built to theprotocol's specifications to communicate securely and to be usedinterchangeably.
Two varieties of SSH (version 1 and version 2) currently exist. SSHversion 1 makes use of several patented encryption algorithms (however,some of these patents have expired) and is vulnerable to a well knownsecurity exploit that allows an attacker to insert data into thecommunication stream. The OpenSSH suite under Red Hat Enterprise Linux uses SSH version 2by default because this version of the protocol has an enhanced keyexchange algorithm not vulnerable to the same exploit. However, theOpenSSH suite does also support version 1 connections.
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It is recommended that only SSH version 2-compatible servers and clients are used whenever possible. |
