I’ve started using Calibre, which is an ebook library management program on PC. It has a feature called “Content Server” through which I can use my phone to access my library stored on my PC. I believe the protocol is called OPDS.

There is a username and password setup for access, but I get a warning that both are sent over the internet unencrypted. For the record I use a VPN, and have private relay turned on for iCloud if that’s worth anything.

My first question is: if username and password are sent unencrypted, does that mean the rest of the traffic is also unencrypted? (Searches, and ebook downloads). If I use a VPN is it still unsecure? My primary concern is if the WiFi owner can theoretically be able to know what I’m doing.

My second question is: is there anything I can do to secure myself further while using this program? I have windows firewall set for public and private connections for this program.