Lion Cipher Lab
Log in with SSH keys instead of passwords
- Identity & Access Management
- Beginner
- ~40 min
- Free · no account required
Why it matters
Remote login is how almost every server on earth is administered, and for decades the default way in was a password — the single credential an attacker can phish out of a person or hammer at until it breaks. Public-key authentication removes that weak point entirely: there is no shared secret to steal or guess, because the private half never leaves your machine and the server only ever sees the public half. Generating a key pair, deploying it to a box you own, and then switching that box to keys-only is the everyday, defensive skill behind hardening any server you're responsible for — and…
What you'll learn
- SSH remote login
- key-based authentication
- ssh-keygen (asymmetric keys)
- ssh-copy-id
- hardening sshd_config
- phishing-resistant access
Steps in this lab
- What SSH is, and why a key beats a password
- Generate a key pair with ssh-keygen (public vs private)
- Look at both halves and learn which one is secret
- Copy the PUBLIC key to your own server (ssh-copy-id)
- Log in with the key, and confirm it worked
- Harden the server: turn off password logins — carefully
- The access mindset to carry forward