If something on a network can be read, in any shape or form, it's been "downloaded". So, no.
What does "restrict the url" mean?
Confluence simply serves up attachments. If those files support password protection, then that can be included before they are uploaded and Confluence will serve them up with that. It does not add any passwords or other protection (beyond "you can log into Confluence and see its content"). There are a couple of add-ons that can add page/attachment protections though, and they may be worth a look.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.