RFC 8591 · PROPOSED STANDARD · 2019

SIP-Based Messaging with S/MIME

Overview

RFC 8591, “SIP-Based Messaging with S/MIME”, is a Proposed Standard document published in April 2019 by B. Campbell, R. Housley. It updates RFC 3261, RFC 3428, RFC 4975. The canonical text is published by the RFC Editor.

Abstract

Mobile messaging applications used with the Session Initiation Protocol (SIP) commonly use some combination of the SIP MESSAGE method and the Message Session Relay Protocol (MSRP). While these provide mechanisms for hop-by-hop security, neither natively provides end-to-end protection. This document offers guidance on how to provide end-to-end authentication, integrity protection, and confidentiality using the Secure/Multipurpose Internet Mail Extensions (S/MIME). It updates and provides clarifications for RFCs 3261, 3428, and 4975.

Abstract as published in the RFC, via rfc-editor.org.

What “Proposed Standard” means

An entry-level standards-track specification: stable, peer-reviewed and a solid basis for implementation, though it may still evolve before becoming an Internet Standard.

Read this RFC

The canonical text of RFC 8591 is hosted at rfc-editor.org. Available in TXT,HTML.

Relationships to other RFCs
This RFC updates
RFC 3261 RFC 3428 RFC 4975
Other RFCs from 2019

Who Is Online

In total there are 59 users online: 0 registered, 52 guests and 7 bots.

Most users ever online was 5,555 on 17 Jul 2026, 3:23 am.

Bots: AhrefsBot Applebot Baiduspider Other Bot Other Spider PetalBot SemrushBot

Users active in the past 15 minutes. Total registered members: 372