Exploring the 'Weakest Link': A Study of Personal Password Security

MSc Thesis (July 2007, revised 6 December 2007)
Gilbert Notoatmodjo

Abstract

The security of most password authentication mechanisms hinges on the secrecy of only a single word – if an adversary obtains knowledge of a victim’s password, the adversary will be able to impersonate the victim and gain access to the resources to which the victim is entitled. Although cryptographic means and protocols offer some degree of protection during the transmission and storage of passwords, users are often left unprotected by nothing but security policies and guidelines which are often neglected. Various literatures have shown that users are the ‘weakest link’ in any password authentication mechanism, due to their propensity to create weak passwords and reuse passwords on multiple accounts. While various identity management solutions have been developed to address the prevalence of users’ insecure password practices, these solutions still suffer from their own problems and drawbacks.

Before we could work towards a more appropriate solution to users’ insecure password practices, it would be necessary to study the underlying cause of these practices, which lies within users’ perceptions of their accounts and passwords. In this thesis, we present the findings from our exploratory, survey-based study, which investigated how user’s perceptions of their accounts and passwords influence their password selection. Our findings revealed that our participants mentally classified their accounts and passwords in several groups based on various perceived similarities. We also discovered that they tended to use passwords that they perceived to be stronger and did not reuse passwords as often in account groups which they considered important.

Appendix A: Application to University of Auckland Human Participants Ethics Committee

Appendix B: Survey Instrument

Appendix C: Dataset