6.26.2009

State of the InterWebz - Authentication and Usability

I am going to divert away from my current JMX saga for a brief moment to discuss an interesting post on the internet that was shared with me regarding usability versus security with masked passwords.

The post, from Jakob Nielsen, states that it is time to do away with password masking to improve usability (post is referenced at the bottom of this post).

This got some interesting conversation going on the webappsec mailing list and got me to thinking about the problem. Jakob has a point in his original post, that as a result of password masking, the average user tends to choose simple passwords to remember (which are quick and easy dictionary cracks) especially if they plan on logging on to the website from their mobile device.

I am sure everyone is aware why password's are masked in just about every type of password type authentication medium across the globe (ie: website logins, OS login, ATM PIN, Alarm Code, etc.) but the main goal is to prevent "shoulder surfers" from easily learning peoples passwords. Arguably, this is a first line of defense only, and not even close to a solution as someone who is good at their craft will be able to get your password just as easily by watching you type it on the keyboard. There are also several other ways that a devious individual may gain access to your password with keyloggers, camera's, or good old fashioned social engineering and simple masking your password bears no protection against these types of recon.

Now don't get me wrong, I am of the mind that having your password masked is a good thing, if we continue to rely on password type authentication. Any security concept should be multi-layered to address as many concerns as possible.

On the iPhone, when you type in a password, it apparently shows the current character you are typing in the form field, then masks it when you move on to the next character. This is an interesting concept and one that has apparantly been adapted on some sites across the internet using a JavaScript hack on a normal form input field.

I am definitely not of the opinion that this is a good idea by any means. Password masking is something that happens at the browser level. A developer simply specifies that a field on a form is of type password, and the browser implements a masking strategy over that field. JavaScript has no place in the security realm, regardless of how harmless it may seem, most of the time when you introduce javascript as a security tool, you open more holes than you close due to the nature of the language and how it interacts with browsers.

This brings me to the point of this post.

We live in a world where every day we grow more and more reliant on the internet to go about our daily lives. We bank online, we shop online, we interact and communicate online, there isn't much that we cannot and in most cases *don't* do online.

The world was a much more seemingly innocent place when the internet was born and no one envisioned that it would be what it is today, and as such, the security model that the internet uses is far too lax to be reliable, no matter how many layers of hacks and crap we put in front of it. There will always be one significant security hole on every web application in the world, in every social network, and on every bank or shopping site.

Humans as a Vulnerability

No matter what we do, the human element will always be there and the average human being has no idea what dangers are lurking around every click he makes on the net. There are a ton of plugins and apps that help to mitigate the risks of using the internet like popup blockers, phishing filters, virus scanners, and so on. These are essential to have installed in any environment, but they do not solve the problem of a poor security model overall, they only patch little leaks in a sinking boat.

Browser manufacturers need to go back to the drawing board when it comes to security and especially when it comes to authentication.

I don't pretend to have all the answers, if I did know the answer, I would be a rich man. I do have thoughts and theories though.

Certificates

Certificates eliminate the need for any human interaction in the authentication space. This, generally, is a good thing provided the human involved can keep his certificates safe. The main problem with using certificates is that support for them in the web space at this point, is shaky at best and there is no good implementation model to use them for authentication to web applications that I have seen. I feel that using certificates is probably the best option that we have in today's world as a first line of defense in our applications when it comes to authenticating users and verifying their identity.

Certificates themselves can also have a password to use, or an empty password for passwordless use. So if you are using a certificate to authenticate and you don't have a password set on the certificate itself, someone only needs gain access to your certificate files to become you.

Password Vaults

Password vaults are a great idea for people who need to remember a lot of passwords. I personally have solved the complex password typing issue completely on my blackberry by using it's integrated password vault to manage all my different internet passwords on different sites. The idea behind a password vault is that you only need remember one password, the password to your vault. The vault stores all of your individual passwords (encrypted of course) and sends them to the application when it prompts you for your password. This is a pretty ingenious idea that has been around for quite some time, however it too has it's vulnerabilities.

Your passwords are stored in a file, usually in some type of proprietary encrypted format specific to the password vault application that you are using. And they are of course, protected by a password. If a nefarious individual determined what password vault you were using, and in turn acquired, through some questionable means, your data file and your password (see shoulder surfing, key logging, etc) they could potentially unlock every password to every application you use and thus, become you.

Fingerprinting

Fingerprinting is an interesting concept that covers a wide variety of authentication in the real world. From retinal scanners, to fingerprint scanners, to hardware addresses and device fingerprinting, this is an interesting yet still vulnerable means of authentication.

For example, a good friend of mine bought an HP laptop with a fingerprint scanner and a touch screen. Hmmm. Sounds too easy to me. I quickly was able to demonstrate how in less than a minute I could lift a fingerprint from his monitor, and use it to gain access to his laptop.

We've all seen in the movies when the guy wears contacts fashioned to look like someone else eye bypasses retinal scanning, and while that may be science fiction in most regards, with todays technology it is very possible to create if you have know the right people and they have the right equipment.

Hardware addresses and device fingerprinting are all-to-easy to bypass these days. Wireless access points have shown us how quickly and easy it is to become another device altogether through some quick air sniffing.

So whats the answer?

My theory is that all of the above should be combined, to create a multi-layered authentication engine that is capable of thwarting most would be attackers, or at least making their job a good deal more difficult and time consuming.

What if there was a browser that implemented a secure password vault (I am not talking about the 'Remember This Password' popup that browsers currently have, I am talking about a true password vault with strong encryption). Having a single password to unlock every password would encourage people to put more thought into creating a more complex password that would be much more difficult to crack. When you only need to remember a single password, it is much easier to remember a complex one. Since all interaction with the applications would be handled via the password vault, the actual application passwords could be extremely complex sequences generated randomly by the password vault itself. This would require application developers to change their line of thinking too, and implement a new type of signup functionality and authentication strategy. Perhaps password creation and authentication would happen as a seperate request over a https connection that would create a token on either side of the connection for challenge/response authentication per-request. But I digress..

Now let's take it to the next step. This is where certificates come in. Instead of unlocking the password vault with a password, what if the password vault was unlocked with a certificate. For the end user, if using a password secured certificate this really is a transparent feature to them, as they still enter a single password to unlock every password, however, it adds an additional layer of complexity to the nefarious hackers evil plot to become you. Now in addition to getting your password vault data files, they also have to acquire your private key to unlock the vault.

Already, we have not only improved the usability of authentication on the web, we have easily doubled or tripled the complexity that a hacker must overcome to steal your identity on the web, just by leveraging existing technologies in a way that makes sense for the security model. This is probably good enough, but I am going to take it even one step further, given the nature of what people do on the internet every day, I would like to see something even more secure.

This is where device fingerprinting comes into play. A USB key could be the answer to the problem of human interaction. A lot of people will immediately argue at this point that now authentication on a website requires a physical piece of hardware to be on your person at the point in time which you wish to use the service. This is where I say, yes, precisely.

Think about it this way, most of us live in a house or apartment; and we safeguard our belongings, information, and family by putting a door that locks and requires a key to unlock between ourselves and any would-be intruders. Granted, there are other ways into a house, just as their are other means to steal an identity on the internet, but if a thief had the choice of walking through an unlocked door or breaking a window, which do you think he would choose?

My concept is that browser manufacturers include a means for an end-user to generate a signed certificate, that is a certificate signed by the browser manufacturer itself, that's single purpose is to live on removable storage (ie: USB thumb drives) and unlock their password vault. The end user then slides the USB thumb drive onto their key ring right between their car keys and the key to their deadbolt on their house and voila! Unless you have a habit of leaving the house without your car keys you will most likely have your authentication with you at all times.

Now, I will be the first to admit, this all seems like it would be far too much for say signing on to facebook, however, think about signing on to your bank website, or purchasing items online, or trading stock, updating insurance information, or filing taxes. All these things are sensitive operations that I believe require a great deal more authentication and proof of identity on the web than typing bob303 into a password box on a web form.

Security constraints should always reflect the level of sensitivity of the action that you are trying to take and it should be no more different on the internet. The responsibility lies on the browser manufacturers, the server developers, and the application developers to recognize this and implement something new. I am sure that there are holes in my concept and there are definately ways around it if an application has vulnerabilities outside of it's authentication scheme (ie: session hijacking, cross-site request forgery, etc.) but your authentication is your first line of defense and as such it should be treated with a great deal more respect than it currently is.

I could probably continue on about this for another 50 pages, and perhaps I will have to write a paper detailing my ideas and theories about the general state of security on the web and the mindset of the people that create functionality therein, but for now I think this brings up some interesting topics for debate and conversation and I am anxious to hear other peoples thoughts.

References:

Jakob Nielsen's post on Password Masking versus Usability
http://www.useit.com/alertbox/passwords.html

WebAppSec Consortium (Home of the Web Security mailing list)
http://www.webappsec.org

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