If you have to manage multiply servers via SSH is really annoying to type same password over and over again. The public key exchange can be used for a secure alternative of typing password on each login.
Here is quick tutorial how to do it:
1) First you need to generate private/public key, so enter this command:
The script will ask you to enter a passphrase two times and it will generate two files: ~/.ssh/id_rsa and ~/.ssh/id_rsa.pub (where "~" is a shortcut to user's home directory).
2) Now to use this keypair on a server, try this run this command:
Now you just need to ssh the server. It won't require pass for most of the operations between this two computers.
$ ssh server "mkdir .ssh; chmod 0700 .ssh"
$ scp .ssh/id_rsa.pub server:.ssh/authorized_keys