# Generate ssh public keypair
    $ cd ~/.ssh
    $ ssh-keygen -t rsa -C "EMAIL"
    Filename: EMAIL
    Passphrase: choose appropriate passphrase
    $ ssh-add EMAIL

# Enable ssh-agent
    $ ssh-agent bash
    $ ssh-add ~/.ssh/id_rsa
    $ ssh username@remote

# Change private ssh key passphrase
    $ ssh-keygen -p
    Enter file in which the key is (~/.ssh/id_rsa): test_key
    Enter old passphrase: 
    Key has comment 'test_key'
    Enter new passphrase (empty for no passphrase): 
    Enter same passphrase again: 
    Your identification has been saved with the new passphrase.

# Show fingerprint of specified public key
    $ ssh-keygen -lf /etc/ssh/ssh_host_rsa_key.pub
    2048 fd:52:c5:f0:6b:b5:37:38:d7:93:e8:58:ab:bf:72:52 /etc/ssh/ssh_host_rsa_key.pub
    $ ssh-keygen -lf id_rsa.pub
    2048 e1:0a:a4:27:66:a7:6f:c8:77:cb:8d:d7:bd:f3:8f:d7 id_rsa.pub (RSA)