On 19 Mar 2025, at 10:08, Murray S. Kucherawy wrote: > One of my long-ago drafts on this topic included the envelope as part of > what gets fed to the hash, and thus signed, but never adds it to the > signature or any other header field. That binds the signature to the > envelope recipient without ever revealing it. I think it also provided > that if there were many recipients, they should be sorted before being > hashed.
I’d still be concerned about the confidentiality of the bcc recipient addresses. If a recipient wanted to ask, “Did Bob get bcc’ed on this?” they could potentially find out by trying to add Bob’s email address and seeing if the hash matched. -Jim _______________________________________________ Ietf-dkim mailing list -- ietf-dkim@ietf.org To unsubscribe send an email to ietf-dkim-le...@ietf.org
