[mailmaint] Question about dual SHA algorithm requirement in draft-ietf-mailmaint-pacc-01
Michel Le Bihan <michel@lebihan.pl> Tue, 21 October 2025 13:37 UTC
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Date: Tue, 21 Oct 2025 15:37:47 +0200
From: Michel Le Bihan <michel@lebihan.pl>
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Subject: [mailmaint] Question about dual SHA algorithm requirement in draft-ietf-mailmaint-pacc-01
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Hi all, I've been reading through draft-ietf-mailmaint-pacc-01 and I'm wondering about the requirement in Section 5.2.1.2.2.3 that servers MUST publish DNS records for both SHA-256 and SHA-512 algorithms. SHA-256 is generally considered future-proof for this kind of use. If we run into a situation where SHA-256 breaks, I'm not convinced SHA-512 would fare much better since they're both from the same SHA-2 family. It seems like requiring both just complicates deployments without giving much real benefit. Is there a specific threat model I'm missing here? Would it make more sense to require SHA-256 and allow the others as optional? Thanks, Michel Le Bihan
- [mailmaint] Question about dual SHA algorithm req… Michel Le Bihan