great tutorial @themarkymark!  I love SSH Public Key Authentication.  It's the first thing I do when setting up a new linux system.  I did it so many times I just have a bash script that modifies all the ssh settings and installs my public key.

I've never seen the distinction between ed25519 and rsa, I'm going to have to do some more reading on that.  I've always just used a high key length rsa algorithm for my keys.  Thanks for bringing that to my attention, I now know what I'm spending my weekend reading about!