Pay per View Distribution of Rolling Stones

One of the first times the Mbone gained exposure on TV and in newspapers was when the Rolling Stones provided an Mbone feed of their [Which venue, altamont?] concert on the Voodoo Lounge tour. Mick and Keith strutted and posed over the nascent multicast network, and the audience whooped in appreciation. The next time the Stones appear on the Internet, they may be selling a pay per view distribution of the event. In a similar fashion to cable or satellite tv pay per view events, only the punters who have paid the fee should be able to see this event. For satellite and cable, this is achieved by encrypting the tv signal, and handing out the decryption key for money. In a similar fashion, the multicast multimedia extravaganza would be encrypted and could only be decrypted by those who had paid for the decryption key.

What are the requirements here? Obviously, we need to be able to encrypt and decrypt the stream. A subtler requirement is the need to distribute keys in a scalable manner - in a world of information, it is unlikely that the key would be contained in a physical medium such as a smart card for a large consumer event, since the physical distribution costs would be large. Instead, the keys would be distributed to the millions using the same Internet. Since the distributors would be encouraging people to sign up at any time, the key distribution mechanisms would need to scale and not melt down upon receiving too many requests.^10.3