How can i prevent users from downloading or accessing a file using "direct targeting" URLs? Using Web.config change?

Hello Guys, I want to prevent user from downloading or accessing a file using "direct targeting" URLs.

I have tried many ways but still i didn't get proper solution.

Here is my code of web.config but still this is not working.

<security>
      <requestFiltering>
          <fileExtensions applyToWebDAV="false">
                 <add fileExtension=".exe" allowed="false" />
                 <add fileExtension=".dll" allowed="false" />
                 <add fileExtension=".xlsx" allowed="false" />
                 <add fileExtension=".xls" allowed="false" />
                 <add fileExtension=".ppt" allowed="false" />
                 <add fileExtension=".pptx" allowed="false" />
                 <add fileExtension=".pdf" allowed="false" />
                 <add fileExtension=".tiff" allowed="false" />
            </fileExtensions>
       </requestFiltering>
</security>

I want to prevent above mentioned files but still this code is not working for me. If anyone have idea that how to prevent to access then please let me know.

*Note : This files should be access in application.

Please provide any solution for this.

Thanks,

Aniruddhsinh