Make your password strong, with a unique jumble of letters, numbers and punctuation marks, but memorize it — never write it down and, oh yes, change it every few months.
These instructions are supposed to protect us, but they don’t.
Some computer security experts are advancing the heretical thought that passwords might not need to be “strong,” or changed constantly. They say onerous requirements for passwords have given us a false sense of protection against potential attacks. In fact, they say, we aren’t paying enough attention to more potent threats.
Here’s one threat to keep you awake at night — keylogging software. It is deposited on a PC by a virus, records all the keystrokes — including the strongest passwords you can concoct — and then sends the data surreptitiously to a remote location.
“Keeping a keylogger off your machine is about a trillion times more important than the strength of any one of your passwords,” says Cormac Herley, a principal researcher at Microsoft Research who specializes in security-related topics.
He said antivirus software could detect and block many kinds of keyloggers, but “there’s no guarantee that it gets everything.”
After investigating password requirements in a variety of settings, Herley is critical not of users, but of system administrators who aren’t paying enough attention to the inconvenience of making people comply with arcane rules.
“It is not users who need to be better educated on the risks of various attacks, but the security community,” he said at a meeting of security professionals, the New Security Paradigms Workshop, at Queen’s College in Oxford, England. “Security advice simply offers a bad cost-benefit trade-off to users.”
One might guess that heavily trafficked Web sites — especially those that provide access to users’ financial information — would have requirements for strong passwords, but it turns out that password policies of many such sites are among the most relaxed.
These sites don’t publicly discuss security breaches, but Herley said it “isn’t plausible” that these sites would use such policies if their users weren’t adequately protected from attacks by those who do not know the password.
Herley, working with Dinei Florencio, also at Microsoft Research, looked at the password policies of 75 Web sites. At the Symposium on Usable Privacy and Security, held in July in Redmond, Washington, they reported that the sites that allowed relatively weak passwords were busy commercial destinations, including PayPal, Amazon.com and Fidelity Investments. The sites that insisted on very complex passwords were mostly government and university sites.
What accounts for the difference?
They suggest that “when the voices that advocate for usability are absent or weak, security measures become needlessly restrictive.”
Donald Norman, one of the cofounders of the Nielsen Norman Group, a design consulting firm in Fremont, California, makes a similar case.
In “When Security Gets in the Way”, an essay published last year in Interactions, he noted the password rules of Northwestern University, where he then taught. It was a daunting list of 15 requirements. He said unreasonable rules can end up rendering a system less secure — users end up writing down passwords and storing them in places that can be readily discovered.