NIST to Revise Special Publication 800-38D | Galois/Counter Mode (GCM) and GMAC Block Cipher Modes
March 05, 2024

In August 2021, NIST's Crypto Publication Review Board initiated a review process for NIST Special Publication (SP) 800-38D, Recommendation for Block Cipher Modes of Operation: Galois/Counter Mode (GCM) and GMAC (2007).

On August 23, 2023, NIST proposed to revise SP 800-38D and received two public comments in response.
NIST has decided to revise SP 800-38D, as proposed, to include the following:

• remove support for authentication tags whose lengths are less than 96 bits,
• clarify that the construction of initialization vectors (IVs) for GCM in the Transport Layer Security (TLS) 1.3 protocol is approved,
• clarify the guidance in connection with the IV constructions, and
• update the references.

Rationale

The public comments on the decision proposal are consistent with the announced plan to revise SP 800-38D, and those comments will be considered as the revision is prepared. NIST will request further public comments when the draft revision is released.

Monitor progress on CSRC News and CSRC Publications, and by subscribing to email updates.

More details of this review are available at NIST’s Crypto Publication Review Project site.