Date of Award


Document Type


Degree Name

Master of Science (MS)

Legacy Department

Industrial Engineering

Committee Chair/Advisor

Greenstein, Joel S

Committee Member

Gramopadhye , Anand K

Committee Member

Cho , Byung Rae


System-generated or user-generated text-based passwords are commonly used by the users to authenticate access to their electronic assets. These passwords may vary in usability and memorability depending on the type of password generation, composition and length. However, little past research has compared usability and memorability of passwords, satisfying minimum entropy for a secure password. This study compared three password policy conditions, assigning/generating passwords of approximately equal minimum security, i.e. 6-character alphanumeric system-generated passwords, minimum 8-character restricted user-generated passwords and minimum 16-character unrestricted user-generated passwords.
The study involved 54 participants, equally divided into three groups, 18 in each password policy condition. The study took place over two sessions, with a period of 5-7 days in between them. In the first session, depending on the password policy condition, the participants were either assigned or asked to create a password. The participants were then asked to recall their passwords in the same session and after 5-7 days in the second session. The three password policy conditions were compared with respect to the dependent variables-- the time taken to create the password account, the password creation error rates, the time taken to recall and recall error rates for both sessions, the number of unrecoverable passwords in the second session, the proximity of the recalled password to the stored password measured by Damerau-Levenshtein and Jaro-Winkler edit distances, and the subjective ratings for the NASA task load indices and the System Usability Scale questionnaire.

Included in

Engineering Commons



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