Gerd Hilgemann from (the company behind VCS Video Communication Server) has just sent me an update on their latest developments. The Germans were hard at work (who'd expect otherwise) implementing a form of DRM protection to the delivery of flv files. It is described as ACP - anti Caching Protection - and adds a VCS license server to the mix of their existing offerings. This server, so I was told, is able to renew or delete license keys at certain intervals which allows pretty detailed control over who can access a certain video file - Flash Video in this case.
Says Gerd: "ACP writes a watermark ID into the flv during streaming to the client. This ID can only be decrypted via a special decoder by Onlinelib. Through this process, the flv file is also being changed in such a way that it cannot be played back reliably by a normal Player, which means that a digital like-for-like copy is not possible.
Onlinelib have released an intial demo which can be seen here.

Having alternatives to Flash Media Server spriing up is a great thing. Competition drives innovation and gives customers a choice - and innovation is clearly what Onlinelib is about. So well done.
However I don't quite 'get' the concept behind this server. I mean if it's a streaming server (like FMS) then why do I need something called anti caching? After all, flv streams are never cached. I therefore have trouble understanding what exactly ACP does. Maybe it grants or denies access to flv streams on a granular level and makes setting up this sort of system easier. But maybe it does more than that (according to the information provided) and modifies the flv stream during streaming. Most experienced FMS developer would know that it is pretty easy to 'download' a flv stream once you have figured out the rtmp adress and stream name - it is possible to rip a remotely served flv stream with the help of (for example) a locally installed FMS.
If ACP does indeed modifiy the streamed flv file then my ripping method may still work to aquire the flv file but most likely (according to Onlinelib) subsequent playback would somehow be prevented or at least disrupted. I'd be keen to see this system in action.

Onlinelib also informed me that this system is compatible with Flash Player 6 and above and that they are working on a AS3 implentation right now.