Earlier quoted context omitted.
I think DMARC works well because email tends to blindly trust DNS (opportunistic encryption). On the web we expect authenticated TLS, often strictly enforced (organization policy, HSTS). So it would feel weird if a website changes how it handles HTTPS cookies based on an insecure DNS record, perhaps delivered by the resolver on an untrustworthy WiFi router. Specifically, if I register subdomain attack.co.uk and set u…
The SVCB HTTPS rfc considers downgrade attacks here: https://www.rfc-editor.org/info/rfc9460/#name-handling-resol... And essentially boils it down to ‘either the client implements wire-security to a known dns server using DoH or DoT, implements dnssec to verify the untrusted response as legitimate, or the client risks being mitm’d to attacker addresses’. They ultimately sidestepped the problem by structuring it to be…
That doesn't sound simple at all.