http://www.rfc-editor.org/rfc/rfc5217.txt
RFC 5217: Memorandum for Multi-Domain Public Key Infrastructure Interoperability, M. Shimaoka, N. Hastings, R. Nielsen2008-07-01T23:00:00-00:00The objective of this document is to establish a terminology framework and to suggest the operational requirements of Public Key Infrastructure (PKI) domain for interoperability of multi-domain Public Key Infrastructure, where each PKI domain is operated under a distinct policy. This document describes the relationships between Certification Authorities (CAs), provides the definition and requirements for PKI domains, and discusses typical models of multi-domain PKI. This memo provides information for the Internet community.