Secure access of webassets with Flask and AWS S3
Make the request to your Flask application, which will authenticate the user and then issue a redirect to the S3 object. The trick is that the redirect should be to a signed temporary URL that expires in a minute or so, so it can't be saved and used later or by others.
You can use boto.s3.key.generate_url function in your Flask app to create the temporary URL.
I am trying to serve files securely (images in this case) to my users. I would like to do this using flask and preferably amazon s3 however I would be open to another cloud storage solution if required. 
I have managed to get my flask static files like css and such on s3 however this is all non-secure. So everyone who has the link can open the static files. This is obviously not what I want for secure content. I can't seems to figure out how I can make a file available to just authenticated user that 'owns' the file.  
For example: When I log into my dropbox account and copy a random file's download link. Then go over to anther computer and use this link it will denie me access. Even though I am still logged in and the download link is available to user on the latter pc.