Today is World Password Day. It’s also Star Wars Day, which will get far more attention from far more people (May the Fourth be with you). It also happens to be National Orange Juice Day. And a few other days. This confusion is appropriate for World Password Day, because while the occasion is about improving password habits, the world has turned decidedly against passwords. Headlines from the past few years demonstrate a consistent stream of invective toward them:
And yet, not one of these efforts has succeeded in “killing the password”—as we can see from the fact that every major online service still requires them.
Why is this the case? To explore this question, it is useful to first examine the function that passwords serve. Online applications must ensure that only authorized users are able to access their data or functionality. In order to do this, the application requires some form of proof that the user who is accessing the application is who they say they are. Passwords are a “shared secret” between the authorized user and the application, and if the user accessing the application demonstrates they know this secret, the application assumes that they are the authorized user. Unfortunately, unauthorized users may learn this shared secret, through various types of attacks, so passwords simply do not provide a good proof of identity. And yet, the password continues to be the universal method of online authentication.
So what about all of the technologies that have gained popularity in recent years, like two-factor authentication using mobile devices and fingerprint scanners? Let’s take a look at some of these alternatives and why they haven’t been able to replace passwords.
Standard biometrics, like fingerprint and iris-based authentication, are convenient in that you always have them available on your person, but you obviously cannot change them. Soft biometrics, like voice and typing pattern analysis, are similar convenient, but have too much variation to be used for anything but negative authentication. Hard and soft tokens, in the form of dedicated hardware or personal mobile devices, are inconvenient to access and often difficult to use. And finally, device-based authentication is also only suitable for negative authentication, since users use multiple devices or may lose their authorized device.
There are some common benefits and drawbacks of these approaches which start to appear. This is because every system for authentication fits into the well-known framework of:
1. Something you know (such as a password)
2. Something you have (such as a mobile phone)
3. Something you are (such as a fingerprint)
The problem is that each part of this framework has different strengths and weaknesses. “Something you know” is convenient and changeable, but it can also be stolen easily, especially if copied somewhere and stored insecurely. “Something you have” is harder to steal, but is also not always with you. And “Something you are” is always available to you, but the description of what you are (say, a scan of your iris) cannot be changed if stolen from an insecure service that stored it. What this means is that the only true replacement for passwords will come from a mechanism that offers the same benefits as “something you know”, and yet somehow addresses its drawbacks.
Security challenge questions: the worst second factor
Some systems have tried to use security challenge questions as an additional authentication factor, especially for password recovery, but these are one of the worst developments in online security. Their problem is that they combine the drawbacks of passwords (answers can be stolen through data breaches), with the drawbacks of biometrics (you can’t change your mother’s maiden name or the street where you grew up), and add their own unique drawbacks (answers can be guessed through social media). Most security professionals now enter random information into such security challenge questions, but that effectively creates additional passwords, which offer no benefit over a single, strong password, except for use as a backup password.
But there is a more fundamental conflict which underpins our continued reliance on passwords: the fact that security and convenience are usually at odds. Moving toward three-factor authentication (one factor from each category), using a combination of something like a password, a soft token, and biometrics, one can create a relatively secure authentication mechanism, but this is much less convenient for most users.
Users value convenience over security (yet still expect security)
For many years, the public has been learning of the need for everyone to select strong passwords. But most people still don’t. Recently, because of the Yahoo and other data breaches, the public started to learn that even if they select strong passwords, they should never reuse them across sites. But most people still do. Password managers aren’t silver bullets, and are subject to their own vulnerabilities, but their widespread use would dramatically improve both of the above issues. Unfortunately, most people don’t use them. Multi-factor authentication, specifically two-factor authentication using mobile phones, is now offered on most major online services. While everyone should enable it, most people won’t, due to the difficulty of use or the lack of convenience.
Security professionals and other security-conscious users are getting more and more options, but the average person continues to value convenience and ease of use above all else, and would like security to simply be provided for them automatically. They don’t want to have to take responsibility for preventing their online bank account from being hacked—they want the bank to take care of that.
In fact, since users will quickly abandon services that are too difficult to use, online services focus much more on improving usability than on security. This is illustrated by a step back in security that technology companies have taken over the years, by standardizing on the use of email addresses as usernames. In the past, you could set a unique username for each account, making it far more difficult for cybercriminals to gain access to your account on one service by stealing your credentials from another. But since remembering both usernames and passwords was hard for users, and online services needed users’ email addresses anyway, they have collectively chosen to consolidate the username and email address into a single identifier. This, of course, has fuelled credential stuffing attacks and automated fraud across all major online services, leveraging billions of spilled credentials through attack tools like Sentry MBA.
The future includes more passwords, for now
The reason that we still have passwords is because we as users continue to demand their advantages, and haven’t come up with anything that preserves those while addressing their drawbacks. Similar to Winston Churchill’s observation on democracy, we might say that passwords are the worst form of authentication—except for all the others that have been tried.
While users are becoming more security conscious, and are learning to accept the friction of multi-factor authentication for the benefit of security, a sea change in user behavior isn’t happening anytime soon. This shifts the burden for security and fraud protection back to online service providers. Given the constraint of delivering a friction-free experience to their users, they are now investing in layered, invisible security mechanisms. These mechanisms allow them to provide the benefits of passwords with defense against their drawbacks, by doing things such as detecting when stolen passwords are used (as recommended by NIST) or protecting against credential stuffing attacks.
It’s World Password Day. While technologies like Apple’s Touch ID afford us great conveniences, and may eventually result in many people being able to bypass re-entering their passwords much of the time, they do not replace those passwords. We’re not “killing” the password anytime soon, so this May 4th, let’s make sure we continue to promote good password practices.