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Pre-Draft Call for Comments on the GCM and GMAC Block Cipher Modes of Operation
NIST requests public comments on whether to pursue one or both approaches (GCM and GMAC).The public comment period closes on March 14, 2025.
In March 2024, NIST announced its intention to revise NIST Special Publication (SP) 800-38D, Recommendation for Block Cipher Modes of Operation: Galois/Counter Mode (GCM) and Galois Message Authentication Code (GMAC) (2007). See NIST’s Crypto Publication Review Project site for information about the review.
NIST requests public input on whether to specify variants of GCM that improve its suitability for today’s highest throughput applications. Two approaches are outlined in this announcement:
- Adapting GCM to the eventual approval of a block cipher with 256-bit blocks and
- Explicitly endorsing a suitable nonce-key generation method.
NIST requests public comments on whether to pursue one or both approaches. Comments may be submitted to ciphermodes [at] nist.gov (ciphermodes[at]nist[dot]gov) by March 14, 2025, with the Subject “Comments on SP 800-38D.” Comments received in response to this request will be posted on this site after the due date. Submitters’ names and affiliations (when provided) will be included, while contact information will be removed.
See today's full announcement for complete details.