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BitTorrent v2

blog.libtorrent.org

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Re: BitTorrent v2

#351

Post by wsc981 »

sanderjd wrote: post #267
nicbou wrote: post #257

Earlier quoted context omitted.

It has been a few years, and despite a few attempts, I still don't really understand bitcoin. Yes yes ledgers and proof of work and yada yada, but I still don't know what I would need to do to buy something with bitcoin right now. As I understand I need to do something that's pretty much exactly like opening a bank account, but transactions take forever, they cost money, and the currency is not accepted by any busine…

It's simple: it is an abject failure as a currency. It is fairly successful as a security for the purpose of speculation. If you aren't a financial speculator, you really don't need to pay attention to it.

I feel it's also a pretty decent store of value. Now some people will probably want to tell me that it's a bad store of value, since the value can fluctuate quite a bit on a day-to-day basis. Sure that true, but in the long run I am confident the value will only go up, whereas many fiat currencies will only go down, especially now due to QE (basically printing money) that's happening in Eurozone, the US, and many other regions [0][1] in the world as well.

So in my view, it's pretty nice as an alternative to holding gold. Gold can be nice as well of course, but it's difficult to transport. If you keep gold in your home, at some point someone might break into your home and steal your gold. You could pay some company to store your gold, but perhaps in times of crises a government might step in and claim some of your gold.

Crypto currencies can be easily held in a digital wallet or people can even just memorise the keys to their wallet in their brain. It's hard for governments to control crypto currencies and I'm sure some of the wealthiest people in the world now keep a certain small percentage of their wealth in cryptos as well as a hedge against fiat currencies, stock market crashes, etc...

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[0]: https://news.bitcoin.com/venezuela-bitcoin-use-hyperinflatio...

[1]: https://www.financemagnates.com/cryptocurrency/the-impact-of...

Re: BitTorrent v2

#352

Post by dmix »

rolleiflex wrote: post #83

I make P2P tools too. [0] Let me tell you this: Bittorrent is one of the few things in the space that actually ... works. It works not in the sense that there is a white paper that should work. Not in the sense that there are a few company-made swarms hosted on industrial servers that keep everyone up and alive, so that the thing gives the impression the 'P2P' network does work. Not in the sense that there is a very-…

Off-topic but it was fun reading your original HN submission from 2013 announcing your project: https://news.ycombinator.com/item?id=6787807

Re: BitTorrent v2

#353

Post by doomrobo »

fenomas wrote: post #344
doomrobo wrote: post #291

Earlier quoted context omitted.

Hashes are now 256 bits. In order to get a collision with probability 1% you need to produce about 4e37 hashes. For comparison, if you had a 5GHz computer that did a SHA-256 hash every cycle and gave 100 of these computers to every human on Earth, it'd take over 300 million years to produce 4e37 hashes.

> In order to get a collision with probability 1% you need to produce about 4e37 hashes Does "get a collision" here mean finding a particular collision with a known hash, or finding any collision between any two of the generated hashes?

The latter. I used the formula from the Wikipedia page on the birthday attack: p ~= 1 - e^{-n^2/2H} where n is the number of items you've picked and H is the size of the universe

Re: BitTorrent v2

#354

Post by dmix »

> It is possible to include both a v1 (btih) and v2 (btmh) info-hash in a magnet link, for backwards compatibility.

The amount of effort into backward compat and keeping the general UX the same (ie: no overly-large new Magnet urls) is really appreciated.

Hopefully this will find quick adoption in both clients and submissions.

Re: BitTorrent v2

#355

Post by octoberfranklin »

DevX101 wrote: post #145
rolleiflex wrote: post #83

I make P2P tools too. [0] Let me tell you this: Bittorrent is one of the few things in the space that actually ... works. It works not in the sense that there is a white paper that should work. Not in the sense that there are a few company-made swarms hosted on industrial servers that keep everyone up and alive, so that the thing gives the impression the 'P2P' network does work. Not in the sense that there is a very-…

BitTorrent was one of the few things that once I understood how it worked, I realized I was looking at the product of true genius.

I know that feeling; I first got it reading this paper by some guy named Nakamoto.

Re: BitTorrent v2

#356

Post by aurelian15 »

sedatk wrote: post #294
Thorentis wrote: post #248

Earlier quoted context omitted.

This right here is the biggest new feature in my opinion, and should have been discussed in more depth in the announcement. I also think they should have pursued this avenue further before releasing v2. Content addressing is one of the big advantages of p2p applications, and IPFS has been pushing it for a long time. Just imagine if this was done all the way down to the piece level. You have two different torrents (sa…

Only if blocks have the same offset in the same binary and if they align with the block boundaries. Otherwise, different hashes would be generated. I don't expect that to happen a lot.

There are ways around this. See "content-aware chunking", e.g. implemented using rolling hashes [1]. This is for example what rsync does.

The idea is to make blocks (slightly) variable in size. Block boundaries are determined based on a limited window of preceding bytes. This way a change in one location will only have a limited impact on the following blocks.

[1] https://en.wikipedia.org/wiki/Rolling_hash

Re: BitTorrent v2

#357

Post by Volt »

crest wrote: post #295
proverbialbunny wrote: post #25

It feels like this isn't a large enough leap forward. It would be nice if BitTorrent v2 made it harder for ISPs to identify what is bit torrent traffic. AT&T artificially slows down upload speeds.

Switch ISP or retire its management by any means necessary.

Switch to what?

Re: BitTorrent v2

#358

Post by octoberfranklin »

godzillabrennus wrote: post #149
rolleiflex wrote: post #83

I make P2P tools too. [0] Let me tell you this: Bittorrent is one of the few things in the space that actually ... works. It works not in the sense that there is a white paper that should work. Not in the sense that there are a few company-made swarms hosted on industrial servers that keep everyone up and alive, so that the thing gives the impression the 'P2P' network does work. Not in the sense that there is a very-…

Hacking around distributed hash table open source software gave me the utmost respect for the people who came up with this stuff. Crypto currencies owe a lot of their successes to the pioneers behind technologies that also power bit torrent.

It's been said that git, bittorrent, and proof-of-work were the three necessary prerequisites for the discovery of blockchains.

Re: BitTorrent v2

#359

Post by fenomas »

doomrobo wrote: post #353
fenomas wrote: post #344

Earlier quoted context omitted.

> In order to get a collision with probability 1% you need to produce about 4e37 hashes Does "get a collision" here mean finding a particular collision with a known hash, or finding any collision between any two of the generated hashes?

The latter. I used the formula from the Wikipedia page on the birthday attack: p ~= 1 - e^{-n^2/2H} where n is the number of items you've picked and H is the size of the universe

I see, thanks!

Re: BitTorrent v2

#360

Post by rolleiflex »

dmix wrote: post #352
rolleiflex wrote: post #83

I make P2P tools too. [0] Let me tell you this: Bittorrent is one of the few things in the space that actually ... works. It works not in the sense that there is a white paper that should work. Not in the sense that there are a few company-made swarms hosted on industrial servers that keep everyone up and alive, so that the thing gives the impression the 'P2P' network does work. Not in the sense that there is a very-…

Off-topic but it was fun reading your original HN submission from 2013 announcing your project: https://news.ycombinator.com/item?id=6787807

Ha, it‘s been awhile. Funny how the world changes.
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