openpgp B. R. Einarsson Internet-Draft Mailpile ehf Intended status: Informational juga Expires: 6 March 2026 Independent D. K. Gillmor ACLU 2 September 2025 (Deprecated) Protected E-mail Headers draft-autocrypt-lamps-protected-headers-04 Abstract This is a tombstone document of an abandoned effort to provide end- to-end cryptographic protections for e-mail headers. It has been superseded by RFC 9788. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 6 March 2026. Copyright Notice Copyright (c) 2025 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Einarsson, et al. Expires 6 March 2026 [Page 1] Internet-Draft (Deprecated) Protected E-mail Headers September 2025 Table of Contents 1. This Document Is Deprecated . . . . . . . . . . . . . . . . . 2 2. References . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.1. Normative References . . . . . . . . . . . . . . . . . . 2 2.2. Informative References . . . . . . . . . . . . . . . . . 2 Appendix A. Document History . . . . . . . . . . . . . . . . . . 2 Appendix B. Acknowledgements . . . . . . . . . . . . . . . . . . 3 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4 1. This Document Is Deprecated This document has been superseded by [RFC9788]. 2. References 2.1. Normative References [RFC9788] Gillmor, D. K., Hoeneisen, B., and A. Melnikov, "Header Protection for Cryptographically Protected Email", RFC 9788, DOI 10.17487/RFC9788, August 2025, . 2.2. Informative References [Autocrypt] "Autocrypt Specification 1.1", 13 October 2019, . [OpenPGP-Email-Summit-2019] "OpenPGP Email Summit 2019", 13 October 2019, . [xkcd936] Munroe, R., "xkcd: Password Strength", 10 August 2011, . Appendix A. Document History Significant changes between version -03 and -04: * Update "Tombstone" to point to released RFC9788. Significant changes between version -02 and -03: * "Tombstone" this document in favor of draft-ietf-lamps-header- protection Significant changes between version -01 and -02: Einarsson, et al. Expires 6 March 2026 [Page 2] Internet-Draft (Deprecated) Protected E-mail Headers September 2025 * Added S/MIME test vectors in addition to PGP/MIME * Legacy Display parts should now be text/plain and not text/ rfc822-headers * Cryptographic Payload must have protected-headers parameter set to v1 * Test vector sample Message-Ids have been normalized * Added encrypted-only (unsigned) test vectors, at the suggestion of Russ Housley Changes between version -00 and -01: * Credit Randall for "correct horse battery staple". * Adjust test vectors to ensure no line in the generated .txt format exceeds 72 chars. * Minor formatting cleanup to appease idnits. * Update references to more recent documents (RFC 2822 -> 5322, -00 to -01 of draft-ietf-lamps-header-protection-requirements). Appendix B. Acknowledgements The set of constructs and algorithms in this document has a previous working title of "Memory Hole", but that title is no longer used as different implementations gained experience in working with it. These ideas were tested and fine-tuned in part by the loose collaboration of MUA developers known as [Autocrypt]. Additional feedback and useful guidance was contributed by attendees of the OpenPGP e-mail summit ([OpenPGP-Email-Summit-2019]). The following people have contributed implementation experience, documentation, critique, and other feedback: * Holger Krekel * Patrick Brunschwig * Vincent Breitmoser * Edwin Taylor Einarsson, et al. Expires 6 March 2026 [Page 3] Internet-Draft (Deprecated) Protected E-mail Headers September 2025 * Alexey Melnikov * Russ Housley The password example used in previous versions comes from [xkcd936]. Authors' Addresses Bjarni Rúnar Einarsson Mailpile ehf Baronsstigur Iceland Email: bre@mailpile.is juga Independent Email: juga@riseup.net Daniel Kahn Gillmor American Civil Liberties Union 125 Broad St. New York, NY, 10004 United States of America Email: dkg@fifthhorseman.net Einarsson, et al. Expires 6 March 2026 [Page 4]