TLS for Secure Element Recursive Authentication

This document defines a recursive authentication architecture based on the TLS 1.3 pre-shared key (PSK) mode. In this context, TLS servers, typically hosted within secure elements (TLS-SE), realize procedures that compute TLS 1.3 PSK-binder and Handshake Secret. These procedures allow a client to authenticate to downstream TLS servers without directly possessing the corresponding PSKs. Authentication capabilities can therefore be delegated across multiple TLS servers while maintaining protection of the underlying secrets.