DARPA, the Defense Advanced Projects Research Agency, realized that the Internet infrastructure needed some work before it could be relied upon even when under active attack. Their Information Technology Office funded a mid-'90s Information Survivability program to work on the issues. Work is still continuing (as of 1997-1998) under their High Confidence Networking project.
Trusted Information Systems' Internet Infrastructure Protection program is one of their contractors. One TIS sub-project is the DNS Security effort. They have produced several prototype implementations of Secure DNS, which are available from their DNS Security Download Site.
John Gilmore is integrating their prototypes into the standard BIND releases.