1. Introduction

Dieser Abschnitt bewahrt den RFC-Text fuer die SSH hybrid key exchange method, einschliesslich sntrup761, X25519, SHA-512, SSH message names, public value lengths, IANA registration, security considerations und test vectors.

1.  Introduction

   Secure Shell (SSH) [RFC4251] is a secure remote login protocol.  The
   key exchange protocol described in [RFC4253] supports an extensible
   set of methods.  [RFC5656] defines how elliptic curves are integrated
   into the extensible SSH framework, and [RFC8731] adds
   curve25519-sha256 to support the pre-quantum Elliptic Curve Diffie-
   Hellman (ECDH) X25519 function [RFC7748].

   Streamlined NTRU Prime [NTRUPrimePQCS] [NTRUPrime] [NTRUPrimeWeb]
   provides post-quantum small lattice-based key-encapsulation
   mechanisms.  The sntrup761 instance has been implemented widely.

   This document specifies a hybrid construction using both sntrup761
   and X25519, in the intention that a hybrid would be secure if either
   algorithms is secure.

   This document also describes how to implement key exchange based on a
   hybrid between Streamlined NTRU Prime sntrup761 and X25519 with
   SHA-512 [RFC6234] in SSH.

   This document was derived from SSH KEX Using Curve25519 and Curve448
   [RFC8731].