Hmm wouldn’t that enable someone to trash your domain reputation if they, say, see said mail on a mailing list and go send spam with the now-public key before the DNS records are removed.
As for use-case, I don’t find it strange that folks may not want to cryptographically sign all their mail without any option to turn that off. It’s certainly not legal protection (as you’d just need to turn your local copies over in discovery anyway), but if folks don’t want to sign their mail, who am I to say otherwise? > On Jul 10, 2020, at 20:52, Matt Palmer via mailop <[email protected]> wrote: > > On Fri, Jul 10, 2020 at 08:57:04PM -0400, Matt Corallo via mailop wrote: >> Hmm, that may have been confusingly worded, I admit. The point is that >> we'd like to publish the private keys after delivery. This means that if >> anyone goes and verifies an email with the DKIM key *after* delivery, they >> learn nothing - anyone could just go download the private key, so anyone >> could forge an email. Of course by this point the keys in DNS would have >> to be gone and TTL-timed-out so no risk of forged mail actually being >> delivered, only making it possible to fake a "DKIM-valid" mail by >> uploading it to gmail via IMAP. > > What about if you publish the private keys *at* delivery, *by* delivery? > That is, use a key-per-message, and send the private key in the message, as > an attachment or similar? It makes a loopy kind of sense, in that the > recipient can hardly say "at the time I received this message, the private > key wasn't known to anyone else" because the private key was definitely > known to at least the recipient. By timestamping the message the recipient > has proven conclusively that the private key wasn't. > > Of course, since you're being fairly cagey about the exact details of this > use case, it's hard to know whether the logic of the argument would work -- > as has been pointed out, people are willing to believe the most wacky stuff, > so the idea that the more abtruse details of key management would convince > whatever audience needs to be convinced isn't necessarily assured. > > - Matt > > > _______________________________________________ > mailop mailing list > [email protected] > https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop _______________________________________________ mailop mailing list [email protected] https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
