---
title: Using Google Authenticator on tilde.club
author: deepend
---


# Using Google Authenticator.

To get started with google authenticator run the following command

  'google-authenticator'
  
Allow the command to update your Google Authenticator. After running the command, you’ll be asked a couple of questions, the first one being:

  'Do you want authentication tokens to be time-based (y/n)'   You need to answer 'yes'(y)
  
You’ll then be presented with a secret key and multiple “scratch codes”. 
We strongly suggest saving these emergency scratch codes in a safe place, 
like a password manager. These codes are the only way to regain access if 
you lose your phone or lose access to your TOTP app, and each one can 
only be used once, so they really are in case of emergency.

You’ll then be prompted with several questions,  The choices are all about balancing security with ease-of-use.
It begins with: 

  'Do you want me to update your "~/.google_authenticator" file (y/n)'
You will need to answer 'yes'(y) for google authenticator to work with your login.

Next question we also suggest answering yes to prevent a replay attack:

  'Do you want to disallow multiple uses of the same authentication 
token? This restricts you to one login about every 30s, but it 
increases your chances to notice or even prevent 
man-in-the-middle attacks (y/n)'

For security reasons we strongly suggest answering 'no'(n) to this next question:

  'By default, tokens are good for 30 seconds and in order to 
compensate for possible time-skew between the client and the server, 
we allow an extra token before and after the current time. If you 
experience problems with poor time synchronization, you can increase 
the window from its default size of 1:30min to about 4min. 
Do you want to do so (y/n)'

On the next question we suggest answering 'yes'(y) since rate-limiting means that a remote attacker can only attempt
a certain number of guesses before being blocked.

  'If the computer that you are logging into isn't hardened against 
brute-force login attempts, you can enable rate-limiting for the 
authentication module. By default, this limits attackers to no more 
than 3 login attempts every 30s. 
Do you want to enable rate-limiting (y/n)'

Now your configured.  Your next login you can login without an SSH key.   Make sure you know your account password
because login using google-authenticator will still require your password before letting you in.