I'm not a blockchain expert, but I don't think it would help in this case. Blockchains are for creating a valid, secure public ledger of transactions. I don't think you want to keep an accurate public log of everything you torrent ;)

You probably want something more like Tor. However Tor's design makes it no good for large transactions thanks to all the obfuscating hops.

There's always a price to pay when attempting to secure something... the trick is making design decisions such that the price is negligible. (Think HTTPS)

I think what he's more talking about is something more akin to a distributed search system than a blockchain - you could make the magnet links last forever in a blockchain, but that doesn't really make sense if no one holds the files anymore you're just keeping useless links around and storing them on every single node for no reason.

A search DHT makes much more sense, look up keywords based on hash. Think the Kademlia network from the ED2K days. Maybe I'm being too academic by even suggesting a DHT be used, you could do it in simpler ways like flood search in the style of Gnutella - any distributed search means would work really.

I believe there are a few attempts at this in the bittorrent world, like Tribler, which is probably the most practical implementation to date, there's a few others too, none of which look particularly mature yet:

https://sourceforge.net/projects/aresgalaxy/editorial/?sourc... https://github.com/lmatteis/torrent-net https://github.com/boramalper/magnetico

The problem with distributed search is that perfecting it is hard - bittorrent has won out because websites could be used to prevent spamming of malware, track reputation and discussion of torrents and individuals, etc. Tribler has some proposed alternatives here and I seem to remember Kad having done a decent job preventing this from becoming a significant problem, but it never had the popularity.

If someone manages to knock out all the big torrent and usenet indexes overnight, these systems will become a lot more necessary and probably get a lot more popular.

Your crypto tools are as strong as the legal freedom to use them. The time is not that far when cryptography tools were considered like military ammunition and required licenses to export and handle.

Even as legal as they are today, crypto tools are really not widespread. Release the Tobacco & Firearms (and their respective equivalent in different countries) and their userbase will shrink into oblivion.