Yeah but URLs are not intended to secure data. They tend to leak out in unexpected ways.
Did you know Google will still index URLs prohibited by robots.txt if it finds a link to them (it just won't crawl them)?
Did you know Google will still index URLs prohibited by robots.txt if it finds a link to them (it just won't crawl them)?
The intent of the URL is that you should bookmark it and otherwise keep it private.
Unless you know of some way for an attacker to get at the browser's bookmark list (which I'd be interested to know about; I'm certainly not enough of an expert to be sure that no such attack exists) then this seems fairly secure.