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Taxonomic Rules for Password Policies: Translating the Informal to the Formal Language
Published
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.
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 8, 2025)