Random URLs to hide assets [duplicate]

Say I own a domain name www.example.com and I’d like to host some resources on it, but being reasonably hidden from the public.

Since a 256 bits has a sufficiently large entropy to prevent an exhaustive traversal, is it correct to consider any URL from my website that contains a hash, as hidden and secured ?

For example if I want to temporarily host a secret item on the domain, I could simply put it at

  • Crawlers won’t be able to find it
  • Malicious users won’t be able to find it
  • The URL won’t be published anywhere, so search engines won’t index it (kinda linked to point 1)
  • It won’t be in the sitemap

I’m just wondering if there are any practical applications of that kind of scheme in the real world ?