SCION Association SCION Association Anapaya Systems This document presents the trust concept and design of the SCION _Control Plane Public Key Infrastructure (CP-PKI)_. SCION (Scalability, Control, and Isolation On Next-generation networks) is a path-aware, inter-domain network architecture where the Control Plane PKI handles cryptographic material and lays the foundation for the authentication procedures in SCION. It is used by SCION's Control Plane to authenticate and verify path information, and provisions SCION's trust model based on Isolation Domains. This document describes the trust model behind the SCION Control Plane PKI, including specifications of the different types of certificates and the Trust Root Configuration. It also specifies how to deploy the Control Plane PKI infrastructure. This document contains new approaches to secure path aware networking. It is not an Internet Standard, has not received any formal review of the IETF, nor was the work developed through the rough consensus process. The approaches offered in this work are offered to the community for its consideration in the further evolution of the Internet.