3 ms·

You are confusing checksums with signatures. BitTorrent only verifies that I have a bit for bit copy of the file the torrent was created from, not that the file

by dsl 15y ago

You are confusing checksums with signatures. BitTorrent only verifies that I have a bit for bit copy of the file the torrent was created from, not that the file is an unaltered version of what the author originally released. Additionally, the modern internet no longer needs mechanisms to deal with download corruption beoynd TCP checksums, BitTorrent implements recovery from failed blocks to protect you from a "flaw" of the protocol itself (you can't always trust the origin of the bits). BitTorrent is also overly inefficient as a download protocol. It only makes sense in situations where you have extremely large flash crowds (WoW for example sending multiple GB to 14 million players in a few days) or the original source isn't in a position (legally or technologically) to source more than a few downloads. The final nail in the coffin is the fact that a few major CDNs tried peer-to-peer for content delivery. The major broadband ISPs were none too pleased with their last-mile infrastructure (the most expensive part to deploy mind you) being abused. Their networks were designed for consumption, not distribution.

cookiecaper 15y ago
I didn't confuse checksums and signatures. I understand the difference between a checksum and a cryptographic signature. I'm sorry if "verification" was used outside its normal context, I just felt it was the best descriptor. Secondly, there's been multiple times where I've downloaded a large file and found it was corrupted. Under conventional protocols you can't easily identify the part that is damaged, so even if it's only a small part (because WiFi dropped or whatever), you have to redownload the whole thing. Instead of doing that, I have just created a torrent, uploaded to openbittorrent, and downloaded the few megabytes I still needed. I agree it may not be worth it to torrent small files (maybe <50MB), but I am not so pessimistic. As far as ISPs go, they just have to accept that their customers are going to be uploading much more than they have been and provide whatever infrastructure upgrades are required. I have no pity for that situation and I don't think it's a valid excuse to not see wider-spread usage of BitTorrent as a conventional download mechanism (i.e., baked into browsers, looks like a HTTP download). They can even default browsers to upload at a low rate, like 5Kb/s, or even 0Kb/s, and be fine; the benefits we're discussing now are inherent in the protocol, not necessarily the size of the swarm; we can still expect content providers to provide the machines that upload all of their content and allow seeding as opt-in only, and see big improvements from the usage of the BitTorrent protocol.

by dsl 15y ago

cookiecaper 15y ago

I didn't confuse checksums and signatures. I understand the difference between a checksum and a cryptographic signature. I'm sorry if "verification" was used outside its normal context, I just felt it was the best descriptor. Secondly, there's been multiple times where I've downloaded a large file and found it was corrupted. Under conventional protocols you can't easily identify the part that is damaged, so even if it's only a small part (because WiFi dropped or whatever), you have to redownload the whole thing. Instead of doing that, I have just created a torrent, uploaded to openbittorrent, and downloaded the few megabytes I still needed. I agree it may not be worth it to torrent small files (maybe <50MB), but I am not so pessimistic. As far as ISPs go, they just have to accept that their customers are going to be uploading much more than they have been and provide whatever infrastructure upgrades are required. I have no pity for that situation and I don't think it's a valid excuse to not see wider-spread usage of BitTorrent as a conventional download mechanism (i.e., baked into browsers, looks like a HTTP download). They can even default browsers to upload at a low rate, like 5Kb/s, or even 0Kb/s, and be fine; the benefits we're discussing now are inherent in the protocol, not necessarily the size of the swarm; we can still expect content providers to provide the machines that upload all of their content and allow seeding as opt-in only, and see big improvements from the usage of the BitTorrent protocol.