For optimal security, it is recommended that you use SSH Keys for logging into SSH, rather than passwords. Using SSH Keys makes it harder for a potential intruder to try to access your account or snoop or interfere with your connection.
You can setup SSH Keys via the Terminal program built into Linux or Mac OS X. For Windows, you will need to use a third-party program such as PuTTY, which can be downloaded for free.
Once you setup SSH Keys, you can disable password authentication so that the server only accepts sessions from people with an authorized key.
More details on how to setup SSH Keys can be found in the following articles: