Document sntrup761x25519-sha512@openssh.com

[np22-jpg]

OpenSSH has had support for a new post-quantum key exchange algorithm, sntrup761x25519-sha512@openssh.com, since OpenSSH 8.8. Is there any reason not to recommend it over everything else? Even leading-edge distributions like Fedora do not default to using it as of yet. It appears as though some documentation has been done for it: https://www.ietf.org/archive/id/draft-josefsson-ntruprime-ssh-02.html#section-1

[bjmgeek]

In addition, OpenSSH versions 9.9 and greater support another post quantum key exchange: mlkem768x25519-sha256. More information is at https://www.openssh.org/pq.html