I spent the day creating privaturl, a very cheap way of sharing content with certain recipients but hosting it on the public web. No server needed, it all[1] works on the frontend and relies on you sharing a link/key with the recipients via a secure communication channel (like Signal or Whatsapp).
The encryption is done using AES-GCM. It’s all pretty standard and all the details are on Github anyway,
so go check it out.
There’s zero chance I was the first one to think or code something like this, but I haven’t been able to find any other implementation. If you know of one, let me know!
1: Not all. You need a computer to actually encrypt the page once.