Thanks, it’s late here now but I’ll try to look soon. I didn’t realize significant improvements over Goldberg etc al were really possible. I’ll try to understand that too.

Is there another post somewhere giving a general description of what you are doing?

Do you have a link about your messaging app? And PIR doesn’t conceal the existence of traffic, so it doesn’t seem like the right thing for messaging. It’s more for databases as the name implies. What exactly are you trying to do?

I used proxmox and have played a little with nix and guix, but simplest is just use debian, put /home on a separate logical partition from the system partition so you can reinstall the system without clobbering user files, and as people keep saying, backup early and often.

I’ve worked in security for decades and nobody has ever asked me about certifications. I know a guy with CISSP and he said it has been useful sometimes, but basically I wouldn’t worry too much. Getting more involved with the security stuff where you work will give real experience which is likely more valuable.

Simplest is use /etc/hosts to set up names, if there are just a few.