Switch server access from password authentication to SSH key-based authentication

SSH key-based authentication replaces password login for server access with a cryptographic key pair, closing off brute-force password attacks entirely, since there is no password to guess or crack in the first place.

Password-based SSH access faces constant automated brute-force attempts from across the internet, key-based authentication makes this entire attack category simply not applicable.

How to do it

1. 1
   Generate an SSH key pair

   A standard, well-documented process on any modern operating system.
2. 2
   Add your public key to the server

   Placed in the appropriate authorized keys location for your user account.
3. 3
   Test key-based login works before disabling passwords

   Confirm you can genuinely log in with the key before removing the password fallback.
4. 4
   Disable password authentication entirely

   Once key-based login is confirmed working, this closes the brute-force attack vector completely.