Passwords and Perceptions

The security of many computer systems hinges on the secrecy of a single word – if an adversary obtains knowledge of a password, they will gain access to the resources controlled by this password. Human users are the ‘weakest link’ in password control, due to our propensity to reuse passwords and to create weak ones. Policies which forbid such unsafe password practices are often violated, even if these policies are well-advertised. We have studied how users perceive their accounts and their passwords. Our participants mentally classified their accounts and passwords into a few groups, based on a small number of perceived similarities. Our participants used stronger passwords, and reused passwords less, in account groups which they considered more important. Our participants thus demonstrated awareness of the basic tenets of password safety, but they did not behave safely in all respects. Almost half of our participants reused at least one of the passwords in their high-importance accounts. Our findings add to the body of evidence that a typical computer user suffers from ‘password overload’. Our concepts of password and account grouping point the way toward more intuitive user interfaces for passwordand account-management systems. .