...
The ToIP Trust Registry Query Protocol (TRQP) is a simple read-only protocol developed by the ToIP Trust Registry Task Force that is often called “DNS for trust”. In other words, it is a lightweight protocol for making fast, efficient queries for authoritative information available in trust registries about who trusts whom for what within a specific contextregistries—authoritative sources of information about trust relationships. The purpose of this overview is to provide an understanding of the overall problem space and an explanation of the key concepts covered in the specification.
...