I had to do a similar thing a decade ago when someone started scraping my site by brute force. At the time I was using CoralCDN already, but my server was getting hammered, so I just started serving up assets with hashed URLs and changing the key every 24h--their scraper was dumb enough to not start again from scratch.

I ended up using the exact same code for sharding, and later to move to a static site with Azure Storage (which lets me use SAS tokens for timed expiry if I want to).