5 ms·

Skimming over the code it seems like it's doing fairly egregious bittorrent spec violations. In other words its very selfish and other clients may blacklist it

by the8472 10y ago

Skimming over the code it seems like it's doing fairly egregious bittorrent spec violations. In other words its very selfish and other clients may blacklist it if they detect such behavior.

boramalper 10y ago
> Skimming over the code it seems like it's doing fairly egregious bittorrent spec violations. It's true and even understated: magneticod is not only selfish but also incredibly aggressive. It will literally contact a thousand (and if your network allows, even more) nodes every single second and deceive them by forging thousands of ids to create the impression that it is "very close" (in terms of XOR-distance used in DHT Kademlia) to the every single node. Please have a look at this website (although it is a bit old): https://dsn.tm.kit.edu/english/2936.php https://dsn.tm.kit.edu/english/2936.php There are on average 7,000,000 DHT peers in the network and less than a quarter of the nodes stay longer than 12 hours in the network (i.e. the node you contacted this morning might be long gone at the evening). There are quite a few public papers[0] describing various Sybil-attacks on BitTorrent DHT, so it's not something unknown. BEP 42[1] tries to mitigate the issue by making node IDs dependent on the IP address of the node, but as far as I know not many clients (if any) implements it. I spoke too much but one last point: These attacks -given the scale of BitTorrent DHT- I doubt to be disruptive, but they are more dangerous for the privacy of the peers. One can gather thousands of IP addresses each day as easily using the same technique. (See http://opentracker.blog.h3q.com/2007/02/12/perfect-deniability/ http://opentracker.blog.h3q.com/2007/02/12/perfect-deniabili...) [0]: https://www.usenix.org/legacy/event/woot10/tech/full_papers/Wolchok.pdf https://www.usenix.org/legacy/event/woot10/tech/full_papers/... [1]: http://www.bittorrent.org/beps/bep_0042.html http://www.bittorrent.org/beps/bep_0042.html
- the8472 10y ago
  I'm not sure what you're trying to argue here. That it's ok to misbehave because there are papers describing how to do it? That it's ok to be selfish because there are enough compliant nodes to compensate for it?
  - yebyen 10y ago
    I didn't see anything about "OK" -- it says attacks, right there in the comment. I think "Please Read this" is for magnetico author, or for potentially benevolent PR submitter.
    - the8472 10y ago
      > is for magnetico author Going by the username and github account he is the author.
      - boramalper 10y ago
        I am.
  - boramalper 10y ago
    > That it's ok to be selfish because there are enough compliant nodes to compensate for it? Yes. Of course, I do not have data nor the foresight to claim that its short or long term effects are negligible, but I really doubt if it's not the case. > That it's ok to misbehave because there are papers describing how to do it? Not because of that, but I was pointing out that the technique is nothing new, and probably numerous real attacks of much greater scale (with the intention of actually disrupting the network) using the same techniques must have been launched many times before magnetico. If BitTorrent DHT survived those, surely it is more resilient than you tend to think. ---- I would love to hear the opinion of a BitTorrent developer though. I'll try to e-mail them tonight and ask for their opinion. =)
    - the8472 10y ago
      > Yes. Of course, I do not have data nor the foresight to claim that its short or long term effects are negligible, but I really doubt if it's not the case. And what if people see your solution and try to build an end-user thing out of it so that millions of users could run it at home? When building something in a P2P network you always should consider whether it would still work if the majority of the network behaved like that. > If BitTorrent DHT survived those, surely it is more resilient than you tend to think. Yes, the rain forest is also quite resilient. Nothing wrong with logging a few more trees, right? I'm saying your kind of reasoning is responsible for tragedy of the commons outcomes. You're not even trying to make your nodes a good citizen in the network because "others do it too". -- Anyway, such behavior can be detected and if it becomes more common other clients will probably implement blacklisting for it.
hexmiles 10y ago
is there a way to accomplish this while being peer-friendly? or the nature of this software is possible only by violating the spec and also being "rude" to other peer in the network
- the8472 10y ago
  yes. a) you can run a fully compliant node and passively collect hashes and then do lookups on them (optionally run on multiple IPs to increase throughput) b) implement BEP 51.

by the8472 10y ago

Skimming over the code it seems like it's doing fairly egregious bittorrent spec violations. In other words its very selfish and other clients may blacklist it if they detect such behavior.

boramalper 10y ago

> Skimming over the code it seems like it's doing fairly egregious bittorrent spec violations. It's true and even understated: magneticod is not only selfish but also incredibly aggressive. It will literally contact a thousand (and if your network allows, even more) nodes every single second and deceive them by forging thousands of ids to create the impression that it is "very close" (in terms of XOR-distance used in DHT Kademlia) to the every single node. Please have a look at this website (although it is a bit old): https://dsn.tm.kit.edu/english/2936.php https://dsn.tm.kit.edu/english/2936.php There are on average 7,000,000 DHT peers in the network and less than a quarter of the nodes stay longer than 12 hours in the network (i.e. the node you contacted this morning might be long gone at the evening). There are quite a few public papers[0] describing various Sybil-attacks on BitTorrent DHT, so it's not something unknown. BEP 42[1] tries to mitigate the issue by making node IDs dependent on the IP address of the node, but as far as I know not many clients (if any) implements it. I spoke too much but one last point: These attacks -given the scale of BitTorrent DHT- I doubt to be disruptive, but they are more dangerous for the privacy of the peers. One can gather thousands of IP addresses each day as easily using the same technique. (See http://opentracker.blog.h3q.com/2007/02/12/perfect-deniability/ http://opentracker.blog.h3q.com/2007/02/12/perfect-deniabili...) [0]: https://www.usenix.org/legacy/event/woot10/tech/full_papers/Wolchok.pdf https://www.usenix.org/legacy/event/woot10/tech/full_papers/... [1]: http://www.bittorrent.org/beps/bep_0042.html http://www.bittorrent.org/beps/bep_0042.html

the8472 10y ago
I'm not sure what you're trying to argue here. That it's ok to misbehave because there are papers describing how to do it? That it's ok to be selfish because there are enough compliant nodes to compensate for it?
- yebyen 10y ago
  I didn't see anything about "OK" -- it says attacks, right there in the comment. I think "Please Read this" is for magnetico author, or for potentially benevolent PR submitter.
  - the8472 10y ago
    > is for magnetico author Going by the username and github account he is the author.
    - boramalper 10y ago
      I am.
- boramalper 10y ago
  > That it's ok to be selfish because there are enough compliant nodes to compensate for it? Yes. Of course, I do not have data nor the foresight to claim that its short or long term effects are negligible, but I really doubt if it's not the case. > That it's ok to misbehave because there are papers describing how to do it? Not because of that, but I was pointing out that the technique is nothing new, and probably numerous real attacks of much greater scale (with the intention of actually disrupting the network) using the same techniques must have been launched many times before magnetico. If BitTorrent DHT survived those, surely it is more resilient than you tend to think. ---- I would love to hear the opinion of a BitTorrent developer though. I'll try to e-mail them tonight and ask for their opinion. =)
  - the8472 10y ago
    > Yes. Of course, I do not have data nor the foresight to claim that its short or long term effects are negligible, but I really doubt if it's not the case. And what if people see your solution and try to build an end-user thing out of it so that millions of users could run it at home? When building something in a P2P network you always should consider whether it would still work if the majority of the network behaved like that. > If BitTorrent DHT survived those, surely it is more resilient than you tend to think. Yes, the rain forest is also quite resilient. Nothing wrong with logging a few more trees, right? I'm saying your kind of reasoning is responsible for tragedy of the commons outcomes. You're not even trying to make your nodes a good citizen in the network because "others do it too". -- Anyway, such behavior can be detected and if it becomes more common other clients will probably implement blacklisting for it.

hexmiles 10y ago

is there a way to accomplish this while being peer-friendly? or the nature of this software is possible only by violating the spec and also being "rude" to other peer in the network

the8472 10y ago
yes. a) you can run a fully compliant node and passively collect hashes and then do lookups on them (optionally run on multiple IPs to increase throughput) b) implement BEP 51.