RFC 9709 on Encryption Key Derivation in the Cryptographic Message Syntax (CMS) Using HKDF with SHA-256

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        RFC 9709

        Title:      Encryption Key Derivation in the 
                    Cryptographic Message Syntax (CMS) Using HKDF 
                    with SHA-256 
        Author:     R. Housley
        Status:     Standards Track
        Stream:     IETF
        Date:       January 2025
        Mailbox:    housley@vigilsec.com
        Pages:      13
        Updates/Obsoletes/SeeAlso:   None

        I-D Tag:    draft-ietf-lamps-cms-cek-hkdf-sha256-05.txt

        URL:        https://www.rfc-editor.org/info/rfc9709

        DOI:        10.17487/RFC9709

This document specifies the derivation of the content-encryption key
or the content-authenticated-encryption key in the Cryptographic
Message Syntax (CMS) using the HMAC-based Extract-and-Expand Key
Derivation Function (HKDF) with SHA-256. The use of this mechanism
provides protection against an attacker that manipulates the
content-encryption algorithm identifier or the
content-authenticated-encryption algorithm identifier.

This document is a product of the Limited Additional Mechanisms for PKIX and SMIME Working Group of the IETF.

This is now a Proposed Standard.

STANDARDS TRACK: This document specifies an Internet Standards Track
protocol for the Internet community, and requests discussion and suggestions
for improvements.  Please refer to the current edition of the Official
Internet Protocol Standards (https://www.rfc-editor.org/standards) for the 
standardization state and status of this protocol.  Distribution of this 
memo is unlimited.

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