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Pseudonymous Multicasting
Existing Darknet, F2F or cryptographic P2P technologies use onion (or even garlic) wrapped tunnels between nodes. To put a multicast routing layer on top would obviously have complete tunnels between each hop resulting in huge latencies. That probably doesn't make a difference when distributing large files by BitTorrent but this could be too slow and over the top for real-time oriented information that many are interested such as newscasting. It could be interesting to provide native multicast routing in these darknet technologies in order to improve efficiency of pseudonymous multicasting.