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FIPS 197 (Initial Public Draft)

Advanced Encryption Standard (AES)

Date Published: November 2001 (updated December 19, 2022)
Comments Due: February 13, 2023 (public comment period is CLOSED)
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National Institute of Standards and Technology


As a part of the periodic review of NIST’s cryptographic standards and guidelines, NIST's Crypto Publication Review Board ("Review Board") announced the review of FIPS 197, Advanced Encryption Standard (AES) in May 2021.

NIST proposes to update FIPS 197. An update of a publication is appropriate when it only requires changes to correct errors or clarify its interpretation, and no changes are made to technical content. The proposed changes to FIPS 197 are summarized in below.

public comment period for the draft FIPS 197 update is open through February 13, 2023.  Public comments on the decision to update the FIPS, or on the draft update itself, may be submitted to, with “Comments on Draft FIPS 197 Update” in the subject line. Comments received in response to this request will be posted on the Crypto Publication Review Project site after the due date. Submitters’ names and affiliations (when provided) will be included, while contact information will be removed. See the project site for additional information about the review process.

Summary of the Draft Update of FIPS 197

The version history is summarized in Appendix D of the draft update of FIPS 197. The draft update includes extensive editorial improvements to the version that was published in November 2001, including the following:

  • The frontmatter is modernized, e.g., a foreword and abstract are added.
  • Terms and symbols are defined more comprehensively and consistently.
  • Formatting/typesetting is improved in a variety of ways.
  • Unnecessary formalism is removed.
  • Diagrams are included for the three key schedules.
  • Some references were updated, and additional references were provided.

For more details, see the full announcement of this draft update.



cryptography; encryption; AES; block cipher; confidentiality; Rijndael
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Supplemental Material:
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Document History:
12/19/22: FIPS 197 (Draft)
05/09/23: FIPS 197 (Final)


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