TARGETED BIOMETRIC CHALLENGES

An improved technique tailors a biometric challenge activity to a particular user. The particular user submits electronic input from which an authentication system extracts information concerning traits of the particular user; such traits can include keystroke and swiping patterns, handheld device positions, and place of origin. An authentication server maps values of user attributes such as place of origin, age, and UI device to the extracted traits. The authentication server then selects biometric challenges for the particular user based on user attributes having values which deviate most from a mean value of that attribute taken across a population of users. That is, the authentication server bases biometric challenges on the most distinguishing traits of the particular user.