NIST seeks input on key-derivation revision for security assessment planning

NIST opened a pre-draft comment period on November 4, 2026 for a planned revision of SP 800-108, its recommendation for deriving cryptographic keys using pseudorandom functions. Comments are due December 18, 2026. The announcement is preparation for Revision 2, not a final replacement standard.

NIST points to research concerns involving output indistinguishability and key-control security in certain constructions. It seeks feedback on possible changes to CMAC-based approaches, whether to retain one or both Double-Pipeline constructions, and effects on implementation, validation and interoperability.

For contractors providing ISSO, RMF and security assessment support to federal systems, this is a planning signal: identify where system documentation or supplier evidence relies on SP 800-108 and ask the responsible cryptographic specialists about affected constructions. That is an assessment-planning recommendation, not a finding that a specific product is vulnerable or noncompliant.

The current final publication remains SP 800-108 Revision 1, including the February 2024 update. This pre-draft request does not itself announce changes to module-validation status, a blanket replacement deadline or a procurement opportunity. Teams should follow applicable agency requirements and validation guidance while the revision develops.