Question

Question

In the event your user authentication database becomes public, what are some of the consequences for your users if your users’ passwords were stored as plaintext? Describe how you could have reduced the severity of such an event occurring.

Answer 1

To make it simple, if passwords are in plain text, the security would be compromised by anyone having a glance at it.

Now, you need to remember that website log-in isn't the only access to a database. An attacker might be able to get some information from your database in various ways.

First you need to know that it happens. And a hacker typically won't leave a note saying "hey there, I was here, thanks for the data!". So unless you get to know about it, you can't change your password.

Now let's say that there are more users on your system/website. If you get to know about it, you need to inform all the others. How long would it last between the breach, you getting to know about it, you informing your users, covering the hole, and everyone having changed their passwords?

And if your system is open to the public, you can't rely on users not reusing the same passwords. So not only your lack of security compromised their account on your system, they may compromise their other accounts elsewhere.

Why should not passwords be stored in plaintext?

There are 2 main reasons:

1. If a database dump is obtained, attackers can simply login with the plain-text password in the dump. If the passwords were hashed, the password would first need to be brute-forced.

2. Lots of users reuse passwords, as bad an idea as it is, so your security failure could compromise other systems too.

If I'm a hacker and having access to database, it's unimportant, if the password is secure or not, because a password can be changed

That's only if you get write-access to the database. If you have obtained read-only access, or acquired a backup of the database, you would be able to login with the existing password, but not edit the live database. If the password were properly hashed and salted, you would have to brute-force it first, which if unique and well-secured would be infeasible.

In order to avoid such scenarios, we should always hash and encrypt the user passwords and then store them in database.