Encrypting a Multicast Video Stream?

Samhain138 asks: "My company streams video via multicast in a pretty large network. They have a client program for viewing this video stream. Everything works fine, and since the stream is ISMA MPEG-4, almost any player would be able to view it. Lately, they've been looking for a solution for encrypting the video on-the-fly with minimal delay, however all of the solutions they've come across require something physical (dongle, smart-card) which may cause a problem (we can't physically reach all the viewers and it might also become expensive when we have a lot of viewers). Can Slashdot readers suggest anything that is simple to implement (or buy...)?"

Hi!

[base3]

We'd like to lock up a video stream and charge for it. I figured Slashdot would be the perfect place to ask how to use DRM, and that I'd receive lots of free advice to benefit my corporate masters.

PLONK.