Cryptography Engineering LLC Interisle Consulting Vigil Security, LLC Venafi Unlike earlier versions of TLS, current drafts of TLS 1.3 have instead adopted ephemeral-mode Diffie-Hellman and elliptic-curve Diffie-Hellman as the primary cryptographic key exchange mechanism used in TLS. This document describes an optional configuration for TLS servers that allows for the use of a static Diffie-Hellman private key for all TLS connections made to the server. Passive monitoring of TLS connections can be enabled by installing a corresponding copy of this key in each monitoring device.