Selectively re-using bad passwords is not a bad idea, researchers say

For all the repeated advice to use different, complex password for each online account, users are still opting for easy-to-guess, short ones and use them repeatedly across many websites and online services.

Unfortunately, it seems that security professionals must make peace with the situation, or find another way to make users listen and do as they are counselled.

But is the experts’ advice sound? A trio of researchers from Microsoft Researcher and Carleton University, Ottawa, Canada are of a different mind, and are challenging that long-held belief that every account needs a strong password.

As the number of online accounts opened by each user grows, and many are not open to using password managers, users are finding managing a large password portfolio increasingly burdensome.

“Both password re-use, and choosing weak passwords, remain popular coping strategies,” the researchers noted, and believe that they will continue to be popular. “Both are valuable tools in balancing the allocation of effort between higher and lower value accounts.”

So, they decided to see whether and how these strategies can be used in a correct way, given the users’ fixed and limited “effort budgets.”

And the answer is they can – and the should – but the trick is to re-use simple, memorable passwords for bigger group of accounts of low value, i.e. accounts that, if compromised, will not yield much or very helpful information to attackers.

Complex and unique passwords should be reserved for high-value accounts such as those containing a lot of personal information, financial information, confidential documentation, or email accounts that are used for registering to online services and to which password reset emails of those services are sent.

For more details about their research, check out their whitepaper.