RFC 8551: Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 4.0 Message Specification

This document defines Secure/Multipurpose Internet Mail Extensions (S/MIME) version 4.0. S/MIME provides a consistent way to send and receive secure MIME…

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Outgoing relationships (11 related RFCs)

Obsoletes — RFC 5751: Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 3.2 Message Specification
Normative reference — RFC 8418: Use of the Elliptic Curve Diffie-Hellman Key Agreement Algorithm with X25519 and X448 in the Cryptographic Message Syntax (CMS)
Normative reference — RFC 8419: Use of Edwards-Curve Digital Signature Algorithm (EdDSA) Signatures in the Cryptographic Message Syntax (CMS)
Normative reference — RFC 8550: Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 4.0 Certificate Handling
Informative reference — RFC 2045: Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies
Informative reference — RFC 6838: Media Type Specifications and Registration Procedures
Informative reference — RFC 2634: Enhanced Security Services for S/MIME
Informative reference — RFC 6268: Additional New ASN.1 Modules for the Cryptographic Message Syntax (CMS) and the Public Key Infrastructure Using X.509 (PKIX)
Informative reference — RFC 5083: Cryptographic Message Syntax (CMS) Authenticated-Enveloped-Data Content Type
Informative reference — RFC 5035: Enhanced Security Services (ESS) Update: Adding CertID Algorithm Agility
Informative reference — RFC 5750: Secure/Multipurpose Internet Mail Extensions (S/MIME) Version 3.2 Certificate Handling

Incoming relationships (21 related RFCs)

Updated by, Normatively referenced by — RFC 9788: Header Protection for Cryptographically Protected Email
Normatively referenced by — RFC 8823: Extensions to Automatic Certificate Management Environment for End-User S/MIME Certificates
Normatively referenced by — RFC 9216: S/MIME Example Keys and Certificates
Normatively referenced by — RFC 9481: Certificate Management Protocol (CMP) Algorithms
Normatively referenced by — RFC 8755: Using Commercial National Security Algorithm Suite Algorithms in Secure/Multipurpose Internet Mail Extensions
Normatively referenced by — RFC 9148: EST-coaps: Enrollment over Secure Transport with the Secure Constrained Application Protocol
Normatively referenced by — RFC 9219: S/MIME Signature Verification Extension to the JSON Meta Application Protocol (JMAP)
Normatively referenced by — RFC 9690: Use of the RSA-KEM Algorithm in the Cryptographic Message Syntax (CMS)
Normatively referenced by — RFC 9787: Guidance on End-to-End Email Security
Normatively referenced by — RFC 9936: Use of ML-KEM in the Cryptographic Message Syntax (CMS)
Normatively referenced by — RFC 10003: Certificate Management over CMS (CMC): Transport Protocols
Normatively referenced by — RFC 9709: Encryption Key Derivation in the Cryptographic Message Syntax (CMS) Using HKDF with SHA-256
Informatively referenced by — RFC 9052: CBOR Object Signing and Encryption (COSE): Structures and Process
Informatively referenced by — RFC 9053: CBOR Object Signing and Encryption (COSE): Initial Algorithms
Informatively referenced by — RFC 9483: Lightweight Certificate Management Protocol (CMP) Profile
Informatively referenced by — RFC 8689: SMTP Require TLS Option
Informatively referenced by — RFC 8862: Best Practices for Securing RTP Media Signaled with SIP
Informatively referenced by — RFC 8894: Simple Certificate Enrolment Protocol
Informatively referenced by — RFC 9763: Related Certificates for Use in Multiple Authentications within a Protocol
Informatively referenced by — RFC 9671: Sieve Email Filtering: Extension for Processing Calendar Attachments
Informatively referenced by — RFC 9989: Domain-Based Message Authentication, Reporting, and Conformance (DMARC)