In this episode, Lucas and Luna dive into the practical steps for hardening SSH on Linux servers using FIDO2/U2F security keys. They explain why password and even key-based authentication often fall short, then walk through the setup: generating a key backed by a hardware token, configuring sshd to accept only ed25519-sk keys, and disabling password login. The conversation covers real-world friction points like handling multiple servers, backup authentication methods, and the surprising lesson one sysadmin learned after locking themselves out. By the end, listeners have a concrete, implementable security upgrade for their own infrastructure.