This is the second part in a series on password implementations at real websites, based on my paper at WEIS 2010 with Sören Preibusch.
As we discussed yesterday, dubious practices abound within real sites’ password implementations. Password insecurity isn’t only due to random implementation mistakes, though. When we scored sites’ passwords implementations on a 10-point aggregate scale it became clear that a wide spectrum of implementation quality exists. Many web authentication giants (Amazon, eBay, Facebook, Google, LiveJournal, Microsoft, MySpace, Yahoo!) scored near the top, joined by a few unlikely standouts (IKEA, CNBC). At the opposite end were a slew of lesser-known merchants and news websites. Exploring the factors which lead to better security confirms the basic tenets of security economics: sites with more at stake tend to do better. However, doing better isn’t enough. Given users’ well-documented tendency to re-use passwords, the varying levels of security may represent a serious market failure which is undermining the security of password-based authentication.