Microsoft Sun Microsystems As noted in Roaming Requirements, there is a need for end-to-end secu- rity in roaming, including end-to-end integrity protection, and confi- dentiality. In roaming implementations based on proxy chaining, pack- ets are routed between the NAS and home server through a series of proxies. Current roaming implementations provide only hop-by-hop security, guarding only against modification of packets in transit between hops. This makes it possible for untrusted proxies to modify packets sent between a NAS and a home server without detection, as well as to decrypt PAP passwords, Tunnel passwords, and other hidden attributes which are available to it in cleartext. This document provides a framework for end-to-end security in roaming, making it possible to provide end-to-end message integrity and attribute hiding through addition of three new attributes.