Why Modern SSH Keys Cannot Fix Harvested Traffic

SSH user keys authenticate who you are, but they do not encrypt your session. That distinction matters against harvest-now, decrypt-later attacks, where stored traffic falls to quantum advances targeting ephemeral key exchange rather than your login credentials. A look at the differences between user keys, host authentication, and session negotiation explores what OpenSSH defaults actually protect, why hybrid signatures like ML-DSA require support at both endpoints, and why forward secrecy has its limits. Key sources: • OpenSSH post-quantum page — https://www.openssh.org/pq.html • ssh-keygen(1), current OpenBSD man page — https://man.openbsd.org/ssh-keygen • ssh_config(5) — https://man.openbsd.org/ssh_config Episode 6350 — myweirdprompts.com/n/6350 (permanent short link: myweirdprompts.com/003596)