All things related to multicast

[Dan Pritts <>]

speaking purely theoretically, I have imagined a system where content is
multicast in encrypted format, with the encryption key changing on a
regular basis.  how often depends on how fine-grained user tracking 
you want.

To get the decryption key, you need to have a conversation with the
provider of the content.  That might be as simple as your viewer software
making a SOAP connection to the provider to get the key so you can be
tracked as a recipient, or it might feed a complex DRM mechanism.

If you just wanted to track viewers you could make the encryption trivial
to decrypt, which would lower the barrier to entry for those who want
to view your content.

while a motivated cracker could brute-force it, nobody would be motivated,
since you were giving away the key to anyone who asked.

I say "view" and "viewer" but this is not video-specific.

On Tue, Mar 01, 2005 at 05:55:25PM -0500, Alan Crosswell wrote:
> Aha.  Yes, you discovered this feature of multicast:-)  Depending on your 
> viewing application, it can be set up to explicitly send back tracking 
> information.  One example of this is many RTP clients send RTCP reports 
> back which primarily indicate how well the stream is being received for 
> performance management purposes.  There's also the whole area of rights 
> management, encryption, etc. of pay-per-view and the like which I would 
> like to learn more about from someone and can certainly be envisioned as a 
> tracking mechanism.  Anyone?
> /a
> 
> David Devereaux-Weber wrote:
> >So, we've invented this wonderfully scaleable way to support almost 
> >unlimited viewers...how can we count them?  Are there tools for tracking 
> >multicast viewers?
> >
> >Dave
> >
> >


danno
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dan pritts - systems administrator - internet2
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