I worked at a big streaming media company and there are significant DRM challenges with serving video in a way that protects the content. When you're trying to

I worked at a big streaming media company and there are significant DRM challenges with serving video in a way that protects the content. When you're trying to get serious content deals from producers they will dive into the deepest level of how you handle their content to make sure it meets their own internal standards before agreeing to anything. Companies like BitGravity are developing solutions that meet these requirements. One idea might be to expire the hashes in a 5 minute rolling window which would still give a huge caching advantage to ISPs: 1. ClientA is authorized with video service. 2. ClientA gets 50mb of hashes to buffer 3. ClientA starts downloading hashes sequentially, requesting more hashes from the service as the queue is emptied. 4. ClientB is authorized with the video service. 5. ClientB requests same resource and gets same list of hashes. 6. ISP can cache the hashes for 5 minutes and get some savings for popular content. I think this would be a very good solution for live broadcast where you're looking at a huge number of people requesting the same content, but for VOD it would have limited return.