Enhancing cooperative playback systems with efficient encrypted multimedia streaming

Distributed platforms for live and on-demand media streaming delivery such as content distribution networks and media ondemand systems, are being diffused mainly due to the widespread availability of IP-based, bandwidth-capable digital networks. Provision of multimedia group services is usually supported by transmitting media streams to subscribers organized in a multicast group. Although multicast streaming saves bandwidth and improves scalability, it is prone to be hacked. This paper proposes an efficient technique centered on the Blowfish symmetric encryption algorithm for securing media streams based on the Real-time Transport Protocol (RTP). The developed technique along with an ad-hoc key distribution mechanism is seamlessly embedded into our Java-based cooperative playback system ViCRO, which allows multicast transmission on-demand of archived multimedia sessions to a cooperative group of clients.