Microsoft has rammed a research rod into the security spokes of the internet by advocating for password reuse in a paper that thoroughly derails the credentials best practise wagon.
Password reuse has become a pariah in internet security circles in recent years following a barrage of breaches that prompted pleas from hacked businesses and media outlets to stop repeating access codes across web sites.
The recommendations appeared logical; hackers with email addresses and passwords in hand could test those credentials against other websites to gain easy illegal access.
Now Redmond researchers Dinei Florencio and Cormac Herley, together with Paul C. van Oorschot of Carleton University, Canada, have shot holes through the security dogma in a paper Password portfolios and the Finite-Effort User: Sustainably Managing Large Numbers of Accounts (PDF).
The trio argue that password reuse on low risk websites is necessary in order for users to be able to remember unique and high entropy codes chosen for important sites.
Users should therefore slap the same simple passwords across free websites that don't hold important information and save the tough and unique ones for banking websites and other repositories of high-value information.
"The rapid decline of [password complexity as recall difficulty] increases suggests that, far from being unallowable, password re-use is a necessary and sensible tool in managing a portfolio," the trio wrote.
"Re-use appears unavoidable if [complexity] must remain above some minimum and effort below some maximum."
Password sets should be reused across groups of websites. Those sites holding little personal information could be placed in the users' 'go-ahead-and-hack-me' bucket protected by codes like P@ssword1, while sites where pwnage would trigger fire and brimstone should be protected by complex and unique login credentials.
Hackable groups "should be very exposed" and "should have weak passwords", the researchers said, because pushing users to light up even a small amount of grey matter "would be wasteful".
The Redmond research realises the realities of userland security; People are bad at remembering passwords and seemingly worse at caring about the issue of security.
Research published in 2012 found the average Brit glued the same five passwords to their 26 online accounts while one in 25 used the same code for everything.
The wheels of the best practise wagon appeared anything but well-oiled when the research was married with arguments against regular password resets - common in enterprises - which insisted that forcing change only drove users to opt for weaker codes that were easier to remember.
Moreover, that experts could not agree on what constituted a good password - a nonsensical arrangement of numbers, letters and symbols versus a unique easy to recall sentence - cast further doubt on the question of authentication.
Interested users and algebra fanatics could consult the Remond paper for a thorough explanation of the password research.
An added level of personal security not mentioned in the paper can be achieved by signing up to websites with a consistently fake alias, complete with a similar but altered name, birthdate, and physical and electronic addresses. The impact to users of any breach on these sites would be next to nil. ®