https://macmule.com/2015/05/19/making-the-most-of-mac-mini-for-use-with-the-casper-suite/

ssh-keygen-example

sh-3.2# ssh-keygen -t rsa
Generating public/private rsa key pair.
Enter file in which to save the key (/var/root/.ssh/id_rsa): 
Created directory '/var/root/.ssh'.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /var/root/.ssh/id_rsa.
Your public key has been saved in /var/root/.ssh/id_rsa.pub.
The key fingerprint is:
73:77:c8:83:17:2c:9e:b1:6e:71:2d:bf:68:e7:8e:3b [email protected]
The keys randomart image is:
+--[ RSA 2048]----+
|                 |
|           .     |
|          o o    |
|         . B +   |
|        S B O o  |
|         + = =   |
|          o   .  |
|         .  Eo.. |
|           .+*+  |
+-----------------+