Example

gistfile1.txt

$ ssh-keygen -t rsa -C "your.email@example.com"
Generating public/private rsa key pair.
Enter file in which to save the key (/home/<your_user>/.ssh/id_rsa):    
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/<your_user>/.ssh/id_rsa.
Your public key has been saved in /home/<your_user>/.ssh/id_rsa.pub.
The key fingerprint is:
37:6c:6c:f3:a8:67:20:4f:94:b0:5b:85:fd:6c:8b:e1 your.email@example.com
The key's randomart image is:
+--[ RSA 2048]----+
|         o       |
|      . . o      |
|       o o o     |
|      . +o. +    |
|       +S.O+ .   |
|      o o+E=.    |
|       + .. .    |
|        ..o      |
|        .o       |
+-----------------+