On Fri, 03 Oct 2014 05:28:35 -0400, Anders Kaseorg said:


> This bottom-up algorithm also seems to have a security problem that’s 
> just as bad as one with the top-down algorithm that you rejected below. 
>   Consider the same department.campus.university.edu example, where 
> campus and edu are signed zones, and university is not a zone.

This issue is why trust anchors were devised so people could start deploying
DNSSEC before stuff like .COM got signed.