rfc-4956
DNS Security (DNSSEC) Opt-In
In the DNS security (DNSSEC) extensions, delegations to unsigned subzones are cryptographically secured. Maintaining this cryptography is not always practical or necessary. This document describes an experimental "Opt-In" model that allows administrators to omit this cryptography and manage the cost of adopting DNSSEC with large zones. This memo defines an Experimental Protocol for the Internet community.