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2025-04-23 Minutes of the S/MIME Certificate Working Group

Minutes of SMCWG

April 23, 2025

These are the Minutes of the meeting described in the subject of this message. Corrections and clarifications where needed are encouraged by reply.


1. Note Well and Antitrust Statement


2. Roll Call

  • Taken from recording (Webex). See “Attendees” below.

3. Approval of Prior Minutes

  • Minutes from March 27 (Tokyo F2F and April 9) were approved.
  • Minutes were taken by Stephen Davidson, changing to new template proposed by Ben Wilson.

4. Agenda Review

  • The agenda was reviewed. There were no additions.

5. Membership Applications

  • Ganesh Mallaya (individual) and Antony Vennard (individual) were confirmed as Interested Parties.

6. Discussion Topics

Topic 1: Pkilint feedback: pseudonym The WG discussed feedback that had arisen from pkilint users regarding tagging the use of Pseudonyms in the CN. Stephen presented a draft update that introduced the prefixes Psuedo: and PN: initially as a MAY, and proposed this would become a SHALL at a future date. Stephen noted that this use was already common in Europe, but he was not aware of it being described in any standard.

Judith Spencer and Ashish Dhiman suggested that the prefix should remain a MAY. Stephen noted that on a previous call, a Certificate Consumer had voiced a strong preference for universal consistency if such a tag was be introduced.

Topic 2: Pkilint feedback: directoryName

The group previously discussed a correction to the text relating to the use of directoryName in the SAN extension, where a reference to tables had not been updated to accommodate changes in the number of those tables. Stephen presented draft text proposed by Corey Bonnell. It was agreed to incorporate the correction in an upcoming ballot.

Topic 3: Final review of ACME for S/MIME ballot

Stephen reviewed the draft text to introduce a new method for validation of mailbox control, using ACME for S/MIME as defined in RFC 8823: Extensions to Automatic Certificate Management Environment for End-User S/MIME Certificates. Although similar to the existing method (3.2.2.2) “Validating control over mailbox via email”, the WG agreed to define ACME for S/MIME in a new method in order to better describe how a CA’s ACME server may respond to a POST request by sending the Random Value token components via email and SMTP.

Tadahiko Ito noted that the text may need to provide a more precise definition of entropy. Stephen asked if he could assist in defining that.

Stephen encouraged the proposal of new methods to facilitate the validation of mailbox authorization or control. There were no objections to move ahead to ballot.

Topic 4: PQC for S/MIME

Stephen noted that the WG had agreed at the WG to explore the introduction of the NIST PQC algorithms to the S/MIME BR. Stephen introduced a draft of such enabling text to allow the use of ML-DSA and ML-KEM. He noted that the proposal only included “pure” PQC certificates at this stage. Clint Wilson suggested that additional steps might be undertaken to accommodate composite and hybrid certificates in a future ballot.

Stephen noted that the additions he made were based on the IETF drafts, and requested that members with PQC expertise review the text for accuracy, but also to note if there are additional guardrails that should be expressed relating to PQC.

It was noted that additional PQC algorithms would inevitably arise, which might hasten the need to realign Section 7 to the table-driven model later adopted in the TLS BR.


7. Ballot Status Updates (if applicable)

  • Upcoming Drafts / In Development: SMC012 – ACME For S/MIME
  • In Discussion Period: NA
  • In Voting Period: NA
  • Under IPR Review: SMC011 until May 14, 2025
  • Approved and Effective: NA

8. Next Meeting

Date: Wednesday, May 7 2025 at 11:00 am Eastern Time


9. Any Other Business

  • None

10. Adjournment

  • The meeting was adjourned.

11. Attendees

Adriano Santoni (Actalis S.p.A.), Andreas Henschel (D-TRUST), Andy Warner (Google), Ashish Dhiman (GlobalSign), Ben Wilson (Mozilla), Clint Wilson (Apple), Corey Bonnell (DigiCert), Cynethia Brown (US Federal PKI Management Authority), Guillaume Amringer (Carillon Information Security Inc.), Hazhar Ismail (MSC Trustgate Sdn Bhd), Inaba Atsushi (GlobalSign), Iñigo Barreira (Sectigo), Judith Spencer (CertiPath), Kateryna Aleksieieva (Asseco Data Systems SA (Certum)), Malcolm Idaho (IdenTrust), Martijn Katerbarg (Sectigo), Morad Abou Nasser (TeleTrust), Mrugesh Chandarana (IdenTrust), Nargis Mannan (VikingCloud), Nome Huang (TrustAsia), Ono Fumiaki (SECOM Trust Systems), Peter Miskovic (Disig), Renne Rodriguez (Apple), Rollin Yu (TrustAsia), Sandy Balzer (SwissSign), Scott Rea (eMudhra), Stefan Selbitschka (rundQuadrat), Stephen Davidson (DigiCert), Tadahiko Ito (SECOM Trust Systems), Zurina Zolkaffly (MSC Trustgate Sdn Bhd)

Latest releases
Server Certificate Requirements
SC-084: DNS Labeled With ACME Account ID Challenge (#566) - Mar 13, 2025

BRs release version 2.1.4

Code Signing Requirements
v3.8 - Aug 5, 2024

What’s Changed CSC-25: Import EV Guidelines to CS Baseline Requirements by @dzacharo in https://github.com/cabforum/code-signing/pull/38 Full Changelog: https://github.com/cabforum/code-signing/compare/v3.7...v3.8

S/MIME Requirements
v1.0.8 - Ballot SMC010 - Dec 23, 2024

This ballot adopts Multi-Perspective Issuance Corroboration (MPIC) for CAs when conducting Email Domain Control Validation (DCV) and Certification Authority Authorization (CAA) checks for S/MIME Certificates. The Ballot adopts the MPIC implementation consistent with the TLS Baseline Requirements. Acknowledging that some S/MIME CAs with no TLS operations may require additional time to deploy MPIC, the Ballot has a Compliance Date of May 15, 2025. Following that date the implementation timeline described in TLS BR section 3.2.2.9 applies. This ballot is proposed by Stephen Davidson (DigiCert) and endorsed by Ashish Dhiman (GlobalSign) and Nicolas Lidzborski (Google).

Network and Certificate System Security Requirements
v2.0 - Ballot NS-003 - Jun 26, 2024

Ballot NS-003: Restructure the NCSSRs in https://github.com/cabforum/netsec/pull/35

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