On Sat, 16 Aug 2014, Phillip Hallam-Baker wrote: > On Sat, Aug 16, 2014 at 4:19 PM, Nico Williams <nico@xxxxxxxxxxxxxxxx> wrote: > > On Sat, Aug 16, 2014 at 04:48:54AM +0000, Viktor Dukhovni wrote: > >> Perhaps I should expand the example section to explain opportunistic > >> DANE TLS for SMTP (even if that spec is still some weeks from LC), > >> not just opportunistic TLS. Then people might have a better > >> understanding of how opportunistic authentication works with DANE, > >> and should work generally. I don't want the draft to over-emphasize > >> DANE, it not just about DANE, but leaving out that example may have > >> resulted in text that is a too abstract. > > > > For me DANE is the critical piece to understanding how the OS protocol > > design pattern can raise the floor without lowering the ceiling and > > without encouraging a general reduction of security against active > > attacks. The key lies in DNSSEC's authenticated non-existence > > functionality. > > ??? > > DANE isn't opportunistic security. It is authenticated security policy > and keys. Thats the opposite of opportunistic. There is a protocol design pattern that involves optimistically checking for and using DANE records where they exist, and not using them when their existence has been authoritatively denied. The overall protocol is optimistic, in that the use of DANE is not required, but its benefits are used when available. -Ben