On a single user laptop does it make sense to have a separte password for root and the user?

Question

I have a laptop on which I'm the only user. While installing the laptop I was wondering why I should choose a different password for the root account and user account. My reasoning is:

• The change of finding a valid password doubles if the user and root have different passwords. Of course the salting algorithms make sure that the same password will result in different hashes but still if one starts to guess passwords it increases the change of finding a good one.
• The user has sudo rights so if an hacker finds the user password it can sudo and have the same powers as root. More or less the same is true if the root account is hacked.
• I have disabled the ssh service on this laptop. There are no other ways to login from remote on this machine.
• The filesystem is encrypted with a different password.

What are the flaws in my thought process?

Answer 1

It's all about your own personal risk tolerance and your threat model. In short, you are worried about someone who is physically in possession of your laptop and has guessed your user password, and you want to keep them from having full admin rights. I'm having a hard time coming up with a scenario where that may actually happen, so I can't help but think that you are overthinking this. Moreover, for most personal computers, the user account is typically more critical than admin access;

https://xkcd.com/1200/

Then again, remembering two passwords isn't much harder than memorizing one, so go for it if you want. Just make sure you have a way to copy your data off the machine without needing admin credentials - you'll want to do that if you ever forget your admin credentials and need to reinstall.

Still, I might suggest an alternate solution:

Use a strong password and don't tell it to anyone

Answer 2

Here are some reasons why it may make sense to have different passwords for user and for root.

1. I suppose you are using the normal user account much more often than the root account. If you log in in some public places as normal user, then the probability that somebody sees your password is much higher than the probability to see your root password. Then, if in doubt, you just change you user password, but you can keep the root password. Also if you use your laptop often in public places, you may want to change password regularly, let say every 3 months. Again, in such cases it will not be needed to change also the root password. Thus it may well make sense to have different passwords.

2. If you gave your user in sudo unlimited rights, then having 2 different passwords doesn't help. But if you limited sudo rights to some operations only, then leakage of you user's password is not as dangerous as leaking the root password. Thus it may well make sense to have different passwords

Answer 3

In your case, you probably don't need a password login for your root account as your regular user has unrestricted sudo access.

Some distributions lock the root account password by default, like Ubuntu. And that is probably the safest way to go. You can lock the root password with:

sudo passwd -l root

This will prefix the password hash in your shadow file with ! or !!, depending on your distribution.

Be aware, locking a password is different than deleting a password. An empty password means, you can login without a password. That's probably not what you want. Also worth noting, a locked password is not equivalent to a locked account. A locked password just prevents any logins via password. Logins via SSH keys are still possible, if configured, and also impersonation of root via sudo su - is still possible.

So, yesn't. You actually do not need to care about your root password, if you lock it.