Taxonomic Rules for Password Policies: Translating the Informal to the Formal Language

Published

December 9, 2013

Author(s)

Kevin Killourhy, Yee-Yin Choong, Mary Theofanos

Abstract

A password policy may seem formal in the sense that it is written in a legalistic language, giving the impression of a binding contract. However, such policies are informal in the logical sense that the policy statements are not written in a clear, unambiguous form. In password policy research at the National Institute of Standards and Technology, a formal language has been developed to explicitly capture what is expected of the user. This document presents that formal language grammar and the procedure that has been developed to translate the statements in the informal language of standard password policies to the formal language.

Citation

NIST Interagency/Internal Report (NISTIR) - 7970

Report Number

7970

NIST Pub Series

NIST Interagency/Internal Report (NISTIR)

Pub Type

NIST Pubs

Download Paper

https://doi.org/10.6028/NIST.IR.7970

Local Download

Keywords

authentication, passwords, password policy, password policies, cybersecurity, computer security, password policy formal grammar

Citation

Killourhy, K. , Choong, Y. and Theofanos, M. (2013), Taxonomic Rules for Password Policies: Translating the Informal to the Formal Language, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], https://doi.org/10.6028/NIST.IR.7970, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=914627 (Accessed October 16, 2025)