Conditioned-safe ceremonies and a user study of an application to web authentication

We introduce the notion of a conditioned-safe ceremony. A “ceremony” is similar to the conventional notion of a protocol, except that a ceremony explicitly includes human participants. Our formulation of a conditioned-safe ceremony draws on several ideas and lessons learned from the human factors and human reliability community: forcing functions, defense in depth, and the use of human tendencies, such as rule-based decision making. We propose design principles for building conditioned-safe ceremonies and apply these principles to develop a registration ceremony for machine authentication based on email. We evaluated our email registration ceremony with a user study of 200 participants. We designed our study to be as ecologically valid as possible: we employed deception, did not use a laboratory environment, and attempted to create an experience of risk. We simulated attacks against the users and found that email registration was significantly more secure than challenge question ...

• Type: Conference
• Year: 2009
• Where: SOUPS
• Authors: Chris Karlof, J. D. Tygar, David Wagner
• Keywords: Ceremony, Conditioned-safe Ceremony, Registration Ceremony, Security Privacy, SOUPS 2009