DomainKeys Identified Mail (DKIM) Development, Deployment, and Operations
RFC 5863
Internet Engineering Task Force (IETF) T. Hansen
Request for Comments: 5863 AT&T Laboratories
Category: Informational E. Siegel
ISSN: 2070-1721 Consultant
P. Hallam-Baker
Default Deny Security, Inc.
D. Crocker
Brandenburg InternetWorking
May 2010
DomainKeys Identified Mail (DKIM)
Development, Deployment, and Operations
Abstract
DomainKeys Identified Mail (DKIM) allows an organization to claim
responsibility for transmitting a message, in a way that can be
validated by a recipient. The organization can be the author's, the
originating sending site, an intermediary, or one of their agents. A
message can contain multiple signatures, from the same or different
organizations involved with the message. DKIM defines a domain-level
digital signature authentication framework for email, using public
key cryptography and using the domain name service as its key server
technology. This permits verification of a responsible organization,
as well as the integrity of the message content. DKIM will also
provide a mechanism that permits potential email signers to publish
information about their email signing practices; this will permit
email receivers to make additional assessments about messages.
DKIM's authentication of email identity can assist in the global
control of "spam" and "phishing". This document provides
implementation, deployment, operational, and migration considerations
for DKIM.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Hansen, et al. Informational [Page 1]
RFC 5863 DKIM Development/Deployment/Operations May 2010
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc5863.
Copyright Notice
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Table of Contents
1. Introduction ....................................................4
2. Using DKIM as Part of Trust Assessment ..........................4
2.1. A Systems View of Email Trust Assessment ...................4
2.2. Choosing a DKIM Tag for the Assessment Identifier ..........6
2.3. Choosing the Signing Domain Name ...........................8
2.4. Recipient-Based Assessments ...............................10
2.5. Filtering .................................................12
3. DKIM Key Generation, Storage, and Management ...................15
3.1. Private Key Management: Deployment and Ongoing
Operations ................................................16
3.2. Storing Public Keys: DNS Server Software Considerations ...17
3.3. Per-User Signing Key Management Issues ....................18
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