> I do wonder why a more decentralised approach hasn't taken off.
In a way, it has!
Compared to what it was when it launched 10 years ago, or even what its predecessors (e.g. Napster, Limewire) were, the current TPB is almost completely decentralized, with only one exception.
It stopped running its own tracker years ago, relying on other trackers that don't allow for searching (thus absolving themselves of some of the legal risks).
And TPB has used DHT[0] for many torrents for a while, theoretically eliminating the need for trackers altogether.
So in 2014, The Pirate Bay is now effectively just a search board for magnet links, with usernames and comments attached only to provide some modicum of reputation (and therefore quality). Those magnet links point to content which is then exchanged either in a truly distributed fashion (DHT) or through these third-party trackers.
So the centralization doesn't provide "core functionality" to torrenting per se - it just provides a degree of quality. Nothing's preventing you from sharing magnet links on other forums (heck, you could paste one in an HN comment). But someone needs to be able to trust that what you're posting is, in fact, the content that you say it is and not a virus, honeypot, etc. Any forum that a group of people trust could serve this functionality (Reddit, HN, Yahoo Answers, etc.[1]) instead of TPB. The competitive advantage of TPB is not the content that it has, but the reputation that it's built over the last decade.
There are Silk Road-based alternatives, which use the Silk Road model for guaranteeing reputation. I guess Tor isn't technically "decentralized", but it'd be a small step to modify the Silk Road approach to broadcasting the actual magnet links themselves.
If you want to decentralize the last remaining centralized piece of TPB, you'd have to solve the problem of decentralizing reputation. This is something that's been worked on in a number of areas (e.g. Bitcoin) but remains unsolved. Perhaps the next TPB will use the Bitcoin blockchain, and this could somehow "solve" the issue, but there are a number of kinks that would have to be worked out.
Reputation? For my use case, I evaluate a torrent based on the number of seeders.
You mentioned that anybody can post a magnet link on any forum. Yes. But where do they get that magnet link from in the first place? I mean, obviously the person who creates the torrent has it. Is that the only way?
You mention DHT. My torrent client does that. Hm, is there a client that I can use to "search" DHT? Failing that, is there a way to dump a list of what hashes/magnet links/torrents my own client is currently hearing about?
Sorry for not just googling this, but there's an awful lot of cargo cult information about torrents out there...
You could create a DHT with all known torrents. Kademila was built basically with that in mind. The Kad network works pretty well, but it does face some problems with spam; just sorting by seeders doesn't cut it since a spammer can fake as many seeders as he'd like.
DHT is a way to discover peers who also have pieces of the same torrent you are downloading. It's an alternative to using a centralized Tracker to tell your client about who has the pieces of the file you need.
Yeah. When someone tells me "we must stop this sharing of valuable content!" I answer with something like "Here is all anyone needs to download your content: magnet:?xt=urn:btih:e6da54b1ad507ec6217610dbc71c248a1a49f925"... or whatever the magnet link is for the current LibreOffice ;-)
In a way, it has!
Compared to what it was when it launched 10 years ago, or even what its predecessors (e.g. Napster, Limewire) were, the current TPB is almost completely decentralized, with only one exception.
It stopped running its own tracker years ago, relying on other trackers that don't allow for searching (thus absolving themselves of some of the legal risks). And TPB has used DHT[0] for many torrents for a while, theoretically eliminating the need for trackers altogether.
So in 2014, The Pirate Bay is now effectively just a search board for magnet links, with usernames and comments attached only to provide some modicum of reputation (and therefore quality). Those magnet links point to content which is then exchanged either in a truly distributed fashion (DHT) or through these third-party trackers.
So the centralization doesn't provide "core functionality" to torrenting per se - it just provides a degree of quality. Nothing's preventing you from sharing magnet links on other forums (heck, you could paste one in an HN comment). But someone needs to be able to trust that what you're posting is, in fact, the content that you say it is and not a virus, honeypot, etc. Any forum that a group of people trust could serve this functionality (Reddit, HN, Yahoo Answers, etc.[1]) instead of TPB. The competitive advantage of TPB is not the content that it has, but the reputation that it's built over the last decade.
There are Silk Road-based alternatives, which use the Silk Road model for guaranteeing reputation. I guess Tor isn't technically "decentralized", but it'd be a small step to modify the Silk Road approach to broadcasting the actual magnet links themselves.
If you want to decentralize the last remaining centralized piece of TPB, you'd have to solve the problem of decentralizing reputation. This is something that's been worked on in a number of areas (e.g. Bitcoin) but remains unsolved. Perhaps the next TPB will use the Bitcoin blockchain, and this could somehow "solve" the issue, but there are a number of kinks that would have to be worked out.
[0] https://en.wikipedia.org/wiki/Distributed_hash_table
[1] Notice that these are all centralized