This presents security-related requirements for the I2RS protocol which provides a new interface to the routing system described in the I2RS architecture document (RFC7921). The I2RS protocol is a re-use protocol implemented by re-using portions of existing IETF protocols and adding new features to these protocols. The I2RS protocol re- uses security features of a secure transport (E.g. TLS, SSH, DTLS) such as encryption, message integrity, mutual peer authentication, and replay protection. The new I2RS features to consider from a security perspective are: a priority mechanism to handle multi-headed write transactions, an opaque secondary identifier which identifies an application using the I2RS client, and an extremely constrained read-only non-secure transport. This document provides the detailed requirements for these security features.