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Kill All The Passwords
According to Boyd and his group, a very random 12-character password should be reasonably safe from a GPU-based brute-force attack, at least for now. (Boyd hastened to add that his team wasn’t trying to identify what the best password security policy is, just to demonstrate that relatively short passwords aren’t secure.)
But in the real world, long passwords have the same fatal flaws as short passwords. Users won’t remember a 12-character random password (hey, they can’t remember a seven-character random password). So users will write those long passwords on Post-Its and stick them to their monitors. And spell them out over the phone when they want a co-worker to check their E-mail. And recite them to a stranger in a bar who’s playing a game of “who’s got the weirdest password?”
These aren’t new problems. In the age of the GPU, passwords aren’t safe from brute-force cracking. But passwords have never been safe from social engineering.
So let’s kill them. Passwords appear to be secure, but because of the way many retailers use them, they’re not. Passwords appear to be cheap–no special hardware required!–though that’s only if you don’t measure how much time and manpower your helpdesk spends on password resets.
All you need is a replacement that’s at least as secure and almost as cheap.
That cuts out security fobs and biometric readers. The cheapskates who have kept passwords alive for decades won’t shell out for what they see as pricey hardware. But using a physical artifact is the right idea: those are much harder for employees to accidentally copy or give away.
How about using employee ID cards with a machine-readable element? It can’t be a barcode; any would-be thief with a smartphone could scan that and duplicate it. An RFID tag could be just as risky.
That leaves two technologies that retailers know very well from payment cards: Chip-and-PIN and mag-stripe-and-PIN. Neither is perfect, but both are cheap. Chip-and-PIN requires a separate reader, but it’s likely to be more secure. Mag stripes have the advantage that a PC keyboard with a mag-stripe reader costs about the same as any other PC keyboard; the downside is the risk of skimming.
Best of all, both technologies are familiar to retail IT and to users. And for users, replacing passwords with machine-readable employee IDs would represent a physical change?, one signaling that security is being taken a lot more seriously.
-Marc
August 27th, 2010 at 4:26 pm
The possibilities you describe are years away from being implemented at best, so for the moment passwords are an ugly reality. Luckily, password managers can easily manage hundreds of passwords of any length. The only thing a user needs to remember is the master password. It seems like an easier task to educate users on how to use password managers rather than implement complex security technology on a global basis.
Here’s the simplest way to manage passwords:
Use a password manager to assign unique, random 15 characters for all accounts, protecting them with a strong master password. Once you get into the habit of it, it’s actually faster than how most people login to various accounts each day.
I recently posted a series on password management that highlights this simple solution to the problem, while also giving more background to those who want it (how attackers steal passwords, which password managers are best, etc.):
http://www.filterjoe.com/2010/05/14/password-management-for-the-average-joe/
August 27th, 2010 at 6:10 pm
This article does mention, but does not give enough attention to, the fact that the attacks discussed are only feasible when the encrypted password file can be copied and subjected to an offline attack.
The trick is to have authentication performed on a separate, much more strongly secured host – such as an Active Directory Domain Controller, or a Kerberos server, or a NIS+ server, or even using something as banal as an LDAP-over-SSL authentication dialog.
In these environments, the odds of the “password file” being stolen and subjected to an offline attack go to near zero, and only online attacks may be carried out by the attacker.
With sensible exponential backoff between failed password attempts, lockout after a modest number of failed attempts on a single account, and pattern detection, that minimum 7 character password is quite secure enough.
Passwords aren’t dead yet for security purposes, and they will be with us for a very long while to come for practical purposes. The trick is to employ them correctly.
September 11th, 2010 at 5:28 pm
What the article does not cover are passphrases. Specifically, instead of using lengthy passwords use lengthy passphrases which a user is likely to remember. If I were a pilot (I’m not) I might use:
!_l0ve_fly!ng_my_Cessina
That’s 24 characters. Each word is separated by an underscore, each “i” is replaced by a “!” and each “o” is replaced by a zero (0) and at least one word is capitalized. This is a secure passphrase. In reality, I would expect someone to NOT use a passphrase to which they could be associated. :-)