Re: [freenet-dev] Pitch Black Attack - Analysis, Code, Etc.
On Mon, Jan 28, 2013 at 6:22 PM, Matthew Toseland t...@amphibian.dyndns.org wrote: On Monday 28 Jan 2013 21:39:54 Michael Grube wrote: On Mon, Jan 28, 2013 at 4:14 PM, Matthew Toseland t...@amphibian.dyndns.org wrote: On Monday 28 Jan 2013 18:09:07 Michael Grube wrote: On Sun, Jan 27, 2013 at 12:30 PM, Matthew Toseland t...@amphibian.dyndns.org wrote: On Sunday 27 Jan 2013 05:02:17 Michael Grube wrote: Hi everyone, Around this time last year I started on work to simulate the pitch black attack working against Oskar Sandberg's swapping algorithm that is implemented for use with darknet. The work is essentially incomplete, but I did enough to get an idea of how well Oskar's proposed solution to the Black Attack works. Hopefully the information that follows can provide some insight for anybody working on this problem. It looks like we have a good chance of using Oskar's original plan. Maybe even getting it published, with some help (carl might help even if you don't have time?). The code is messy, so I'm going to do a walkthrough of how exactly I ran the simulation. To start off, my code is available at http://github.com/mgrube/pbsim . Let's start. The first thing I did was create the small world network that is assumed in the darknet. The graph size can obviously be of any size, but in our experiment we'll make the network size 1000 nodes. This is pretty simple in python and can be accomplished with one line in the networkx library: You did check that there isn't a scalability issue? :) I tested with 10,000 nodes as well and the results did not vary by much. The most important difference I noticed was that 2 attackers became a less significant number. Not that this really means anything to a would-be attacker. If you are convinced that scalability is a problem, I can add support for threads to what I have and make it easy to simulate 100,000 or 1M or whatever number we want to try. I don't know. In my experience threads complicate matters quite a bit. Certainly they can. In this case it would help, however. I wonder if it would be worth writing up the natural pitch black via churn evolution we saw in ~ 2008. Basically, when you have churn, newbies end up with the worst locations i.e. those furthest away from the main clusters. So even without an attack, the network locations become more and more clustered. We fixed it by periodic randomisation, which seemed to have relatively little cost - the nodes quickly got their old locations back, more or less. Another thing we want to look into is what the cost is of swapping (especially on a growing network, or even two networks merging) in terms of losing datastores due to locations changing. That might need more detailed simulations... I will see what I can do about looking into these sometime later this week. Good. We can see the aftermath by looking at a histogram of node locations. The randomize function uses a random function to assign each node a location, so first let's look at a histogram of locations before the attack: http://127.0.0.1:/CHK@ODZ1s5SDYrVvyNo0ONh4O9rtI~pcVmTSShh47UFPY5U,SKJfkX2eswHMrqidDWTUoZKGMaZ9yt0l6uLUZMmxOqk,AAMC--8/preattacklocations.PNG Suprisingly wide range of concentrations. The biasing locations for these attack nodes were: .6935 .1935 .9435 .4435 .4665 .9665 .7165 .2165 Our histogram of node locations now shows a disproportionate number of nodes with those locations: http://127.0.0.1:/CHK@aI0BN0NXEjU--8dFtCYZwPwUWcM0rpamIf3lnv7FfHc,SCr2NPJYZVpFJKSf-qDYerQTQyDfdoV3-DeX-W1e91I,AAMC--8/postattack.PNG Scary! Quite. So, the attack with only two nodes is obviously very effective. It's important to note that the attack simulation method assumed that nodes were attacking before the swapping algorithm had a chance to organize the network. This is something of a worst case scenario. So this is attacking after we've done some swapping but not enough to reach the point of diminishing returns? Now, let's measure the effectiveness of Oskar Sandberg's proposed solution, which is described on the bug tracker: https://bugs.freenetproject.org/view.php?id=3919 We can test sandberg's solution by using: sandbergsolution(sandberg_solution_network, attackers, .037) The last parameter, .037 is the distance threshold for re-randomizing a node's location. To be
Re: [freenet-dev] Pitch Black Attack - Analysis, Code, Etc.
On Mon, Jan 28, 2013 at 6:22 PM, Matthew Toseland t...@amphibian.dyndns.org wrote: On Monday 28 Jan 2013 21:39:54 Michael Grube wrote: On Mon, Jan 28, 2013 at 4:14 PM, Matthew Toseland t...@amphibian.dyndns.org wrote: On Monday 28 Jan 2013 18:09:07 Michael Grube wrote: On Sun, Jan 27, 2013 at 12:30 PM, Matthew Toseland t...@amphibian.dyndns.org wrote: On Sunday 27 Jan 2013 05:02:17 Michael Grube wrote: Hi everyone, Around this time last year I started on work to simulate the pitch black attack working against Oskar Sandberg's swapping algorithm that is implemented for use with darknet. The work is essentially incomplete, but I did enough to get an idea of how well Oskar's proposed solution to the Black Attack works. Hopefully the information that follows can provide some insight for anybody working on this problem. It looks like we have a good chance of using Oskar's original plan. Maybe even getting it published, with some help (carl might help even if you don't have time?). The code is messy, so I'm going to do a walkthrough of how exactly I ran the simulation. To start off, my code is available at http://github.com/mgrube/pbsim . Let's start. The first thing I did was create the small world network that is assumed in the darknet. The graph size can obviously be of any size, but in our experiment we'll make the network size 1000 nodes. This is pretty simple in python and can be accomplished with one line in the networkx library: You did check that there isn't a scalability issue? :) I tested with 10,000 nodes as well and the results did not vary by much. The most important difference I noticed was that 2 attackers became a less significant number. Not that this really means anything to a would-be attacker. If you are convinced that scalability is a problem, I can add support for threads to what I have and make it easy to simulate 100,000 or 1M or whatever number we want to try. I don't know. In my experience threads complicate matters quite a bit. Certainly they can. In this case it would help, however. I wonder if it would be worth writing up the natural pitch black via churn evolution we saw in ~ 2008. Basically, when you have churn, newbies end up with the worst locations i.e. those furthest away from the main clusters. So even without an attack, the network locations become more and more clustered. We fixed it by periodic randomisation, which seemed to have relatively little cost - the nodes quickly got their old locations back, more or less. Another thing we want to look into is what the cost is of swapping (especially on a growing network, or even two networks merging) in terms of losing datastores due to locations changing. That might need more detailed simulations... I will see what I can do about looking into these sometime later this week. Good. We can see the aftermath by looking at a histogram of node locations. The randomize function uses a random function to assign each node a location, so first let's look at a histogram of locations before the attack: http://127.0.0.1:/CHK@ODZ1s5SDYrVvyNo0ONh4O9rtI~pcVmTSShh47UFPY5U,SKJfkX2eswHMrqidDWTUoZKGMaZ9yt0l6uLUZMmxOqk,AAMC--8/preattacklocations.PNG Suprisingly wide range of concentrations. The biasing locations for these attack nodes were: .6935 .1935 .9435 .4435 .4665 .9665 .7165 .2165 Our histogram of node locations now shows a disproportionate number of nodes with those locations: http://127.0.0.1:/CHK@aI0BN0NXEjU--8dFtCYZwPwUWcM0rpamIf3lnv7FfHc,SCr2NPJYZVpFJKSf-qDYerQTQyDfdoV3-DeX-W1e91I,AAMC--8/postattack.PNG Scary! Quite. So, the attack with only two nodes is obviously very effective. It's important to note that the attack simulation method assumed that nodes were attacking before the swapping algorithm had a chance to organize the network. This is something of a worst case scenario. So this is attacking after we've done some swapping but not enough to reach the point of diminishing returns? Now, let's measure the effectiveness of Oskar Sandberg's proposed solution, which is described on the bug tracker: https://bugs.freenetproject.org/view.php?id=3919 We can test sandberg's solution by using: sandbergsolution(sandberg_solution_network, attackers, .037) The last parameter, .037 is the distance threshold for re-randomizing a node's location. To be
[freenet-dev] Pitch Black Attack - Analysis, Code, Etc.
Old response that was never forwarded. On Sun, Jan 27, 2013 at 9:06 AM, Arne Babenhauserheide arne_...@web.dewrote: Hi Snark, Thank you for posting! Your analysis looks pretty good. Am Sonntag, 27. Januar 2013, 00:02:17 schrieb Michael Grube: Not bad! There is obviously still some influence but the location distribution has evened out noticeably. There is one down side to this solution, however, and that is that it appears to affect search performance. By how much, I am not sure, but our link length distribution is now looking less ideal: http://127.0.0.1:/CHK@TdODwHOdC9peiHYGtTxDa9yy9v0lXSHKWW4G7wM5-~A,OIy08YxNZdg4M3vpgm7wETOhUvU3RYFzrkJQ7No9poE,AAMC--8/deterioratinglinkdist.PNG What happens if you now apply normal swapping to this distribution? Does it get better or do we see a general problem of swapping? Do you mean without attackers? Changing back to the original swapping method with attackers makes the location distribution fall apart again. Without attackers from this point on, the link length distribution moves back to ideal distribution again. I just ran this again to be sure, but the resulting graph is nothing new, so I didn't insert it. (in some tests while discussing probes, a swapping example I wrote worked well for some stuff, but broke down with certain configurations) The link length distribution could be a pretty big problem… Compare it with the real distribution: http://127.0.0.1:/USK@pxtehd-TmfJwyNUAW2Clk4pwv7Nshyg21NNfXcqzFv4,LTjcTWqvsq3ju6pMGe9Cqb3scvQgECG81hRdgj5WO4s,AQACAAE/statistics/148/plot_link_length.png My first thought is that I'd like to see this graph with link length from 0 to 1. Also, it's important to note that this graph is percent of nodes with that link length or smaller, whereas the graphs I inserted are counts of the number of links with the distance marked on the x axis. This difference might have been obvious to some people, but I just want to be sure everybody sees that. I can't promise anything immediate, but I was already implementing the search algorithm in my simulation. I can try to get some actual numbers by this time next week. Best wishes, Arne PS: I also like it that you used freenet itself for hosting! Of course =) -- Unpolitisch sein heißt politisch sein, ohne es zu merken. - Arne (http://draketo.de) ___ Devl mailing list Devl@freenetproject.org https://emu.freenetproject.org/cgi-bin/mailman/listinfo/devl
Re: [freenet-dev] Pitch Black Attack - Analysis, Code, Etc.
On Thursday 31 Jan 2013 16:16:38 Michael Grube wrote: So how exactly do you use the 0.037 constant? If you don't have a peer with distance greater than 0.037 * (distance from random location to nearest node to the random location), then you reset? (This will break for nodes with very small degree...) No. It's not based on your immediate peer - a probe doing a DFS search returns the closest result to some key that is selected at random. If the closest node identifier to the randomly selected location is further than some distance, the node originating the probe needs to randomize its location. I don't understand. The node originating the search is not the victim. It doesn't have a wrong location. So why does this help at all? Oskar's proposal, as you quoted: From your notes in the bug tracker: Pick a key randomly, route for it with a special query that returns the nearest node identifier to the key found. If the closest you can get is much further than your distance to your neighbors, give up your current position for the random one. The definition of much further needs to be determined experimentally, but it shouldn't be an issue (since the attack in question works by putting a neighbor thousands of times closer to you then it should be). In other words, we use the probe to find out how far we *should* be from our neighbours. Then if we are much too close, we are probably the victim of an attack, so we randomise. signature.asc Description: This is a digitally signed message part. ___ Devl mailing list Devl@freenetproject.org https://emu.freenetproject.org/cgi-bin/mailman/listinfo/devl
Re: [freenet-dev] Pitch Black Attack - Analysis, Code, Etc.
On Thursday 31 Jan 2013 19:24:27 Michael Grube wrote: On Thu, Jan 31, 2013 at 2:06 PM, Matthew Toseland t...@amphibian.dyndns.org wrote: On Thursday 31 Jan 2013 16:16:38 Michael Grube wrote: So how exactly do you use the 0.037 constant? If you don't have a peer with distance greater than 0.037 * (distance from random location to nearest node to the random location), then you reset? (This will break for nodes with very small degree...) No. It's not based on your immediate peer - a probe doing a DFS search returns the closest result to some key that is selected at random. If the closest node identifier to the randomly selected location is further than some distance, the node originating the probe needs to randomize its location. I don't understand. The node originating the search is not the victim. It doesn't have a wrong location. So why does this help at all? The node initiating the search very well could be a vicitm. Yes, if all of their peers are malicious then they are out of options, but assuming most of their trusted peers are not malicious Sandberg's algo works just fine. All nodes with malicious biases should be considered victims, IMO. So when a proportion of the network have bad locations, and therefore there is a gap in the ring, you want an equivalent number of nodes to reset their locations and hopefully fill the gap? Isn't this going to be far less efficient than having *the nodes that are actually affected* reset their locations? I.e. it'll either do far too much resetting or not nearly enough? Oskar's proposal, as you quoted: From your notes in the bug tracker: Pick a key randomly, route for it with a special query that returns the nearest node identifier to the key found. If the closest you can get is much further than your distance to your neighbors, give up your current position for the random one. In other words, we use the probe to find out how far we *should* be from our neighbours. Then if we are much too close, we are probably the victim of an attack, so we randomise. So you're saying we need to calculate the ideal distance with the probes? That is not what I'm reading: The definition of much further needs to be determined experimentally, but it shouldn't be an issue (since the attack in question works by putting a neighbor thousands of times closer to you then it should be). Are you proposing that we estimate network size by using the probes to find the average value of the distance from a randomly selected value and the closest actual result? How does this tell us what the ideal distance should be? AFAICS Oskar's proposal is very clear, at least if it was reported correctly: If (the distance to your neighbours) (arbitrary constant) * (distance from probe), then reset. 'The distance to your neighbours' - You don't use this at all. Hence your interpretation MUST be wrong. 'The closest you can get' - The distance between the target location and the closest node from the probe. 'The definition of much further needs to be determined experimentally' - This is arbitrary constant above. - This is the tunable parameter. Which we will need to experiment with. It's obviously going to be a tradeoff between security and performance. A corrupt network will likely have big gaps covering most of the keyspace. Routing to a random location will likely find us in one of these gaps. On the other hand, the average node should be within the area with normal-ish routing, even in this case - i.e. it should have mostly neighbours that are very close to it. So usually the probe would return a large gap, while our neighbours are close by. And therefore we would reset. But maybe I'm missing something important here... I'm CC'ing devl since this is an important design discussion and there isn't anything confidential here. signature.asc Description: This is a digitally signed message part. ___ Devl mailing list Devl@freenetproject.org https://emu.freenetproject.org/cgi-bin/mailman/listinfo/devl
Re: [freenet-dev] Pitch Black Attack - Analysis, Code, Etc.
On Monday 28 Jan 2013 21:39:54 Michael Grube wrote: On Mon, Jan 28, 2013 at 4:14 PM, Matthew Toseland t...@amphibian.dyndns.org wrote: On Monday 28 Jan 2013 18:09:07 Michael Grube wrote: On Sun, Jan 27, 2013 at 12:30 PM, Matthew Toseland t...@amphibian.dyndns.org wrote: On Sunday 27 Jan 2013 05:02:17 Michael Grube wrote: Hi everyone, Around this time last year I started on work to simulate the pitch black attack working against Oskar Sandberg's swapping algorithm that is implemented for use with darknet. The work is essentially incomplete, but I did enough to get an idea of how well Oskar's proposed solution to the Black Attack works. Hopefully the information that follows can provide some insight for anybody working on this problem. It looks like we have a good chance of using Oskar's original plan. Maybe even getting it published, with some help (carl might help even if you don't have time?). The code is messy, so I'm going to do a walkthrough of how exactly I ran the simulation. To start off, my code is available at http://github.com/mgrube/pbsim . Let's start. The first thing I did was create the small world network that is assumed in the darknet. The graph size can obviously be of any size, but in our experiment we'll make the network size 1000 nodes. This is pretty simple in python and can be accomplished with one line in the networkx library: You did check that there isn't a scalability issue? :) I tested with 10,000 nodes as well and the results did not vary by much. The most important difference I noticed was that 2 attackers became a less significant number. Not that this really means anything to a would-be attacker. If you are convinced that scalability is a problem, I can add support for threads to what I have and make it easy to simulate 100,000 or 1M or whatever number we want to try. I don't know. In my experience threads complicate matters quite a bit. Certainly they can. In this case it would help, however. I wonder if it would be worth writing up the natural pitch black via churn evolution we saw in ~ 2008. Basically, when you have churn, newbies end up with the worst locations i.e. those furthest away from the main clusters. So even without an attack, the network locations become more and more clustered. We fixed it by periodic randomisation, which seemed to have relatively little cost - the nodes quickly got their old locations back, more or less. Another thing we want to look into is what the cost is of swapping (especially on a growing network, or even two networks merging) in terms of losing datastores due to locations changing. That might need more detailed simulations... I will see what I can do about looking into these sometime later this week. Good. We can see the aftermath by looking at a histogram of node locations. The randomize function uses a random function to assign each node a location, so first let's look at a histogram of locations before the attack: http://127.0.0.1:/CHK@ODZ1s5SDYrVvyNo0ONh4O9rtI~pcVmTSShh47UFPY5U,SKJfkX2eswHMrqidDWTUoZKGMaZ9yt0l6uLUZMmxOqk,AAMC--8/preattacklocations.PNG Suprisingly wide range of concentrations. The biasing locations for these attack nodes were: .6935 .1935 .9435 .4435 .4665 .9665 .7165 .2165 Our histogram of node locations now shows a disproportionate number of nodes with those locations: http://127.0.0.1:/CHK@aI0BN0NXEjU--8dFtCYZwPwUWcM0rpamIf3lnv7FfHc,SCr2NPJYZVpFJKSf-qDYerQTQyDfdoV3-DeX-W1e91I,AAMC--8/postattack.PNG Scary! Quite. So, the attack with only two nodes is obviously very effective. It's important to note that the attack simulation method assumed that nodes were attacking before the swapping algorithm had a chance to organize the network. This is something of a worst case scenario. So this is attacking after we've done some swapping but not enough to reach the point of diminishing returns? Now, let's measure the effectiveness of Oskar Sandberg's proposed solution, which is described on the bug tracker: https://bugs.freenetproject.org/view.php?id=3919 We can test sandberg's solution by using: sandbergsolution(sandberg_solution_network, attackers, .037) The last parameter, .037 is the distance threshold for re-randomizing a node's location. To be completely honest I am not sure why, but .037 seemed to work out as a decent experimental distance. This could quite easily change depending on the size of the network and should by no means be used as a default value.
Re: [freenet-dev] Pitch Black Attack - Analysis, Code, Etc.
Hi Snark, Thank you for posting! Your analysis looks pretty good. Am Sonntag, 27. Januar 2013, 00:02:17 schrieb Michael Grube: Not bad! There is obviously still some influence but the location distribution has evened out noticeably. There is one down side to this solution, however, and that is that it appears to affect search performance. By how much, I am not sure, but our link length distribution is now looking less ideal: http://127.0.0.1:/CHK@TdODwHOdC9peiHYGtTxDa9yy9v0lXSHKWW4G7wM5-~A,OIy08YxNZdg4M3vpgm7wETOhUvU3RYFzrkJQ7No9poE,AAMC--8/deterioratinglinkdist.PNG What happens if you now apply normal swapping to this distribution? Does it get better or do we see a general problem of swapping? (in some tests while discussing probes, a swapping example I wrote worked well for some stuff, but broke down with certain configurations) The link length distribution could be a pretty big problem… Compare it with the real distribution: http://127.0.0.1:/USK@pxtehd-TmfJwyNUAW2Clk4pwv7Nshyg21NNfXcqzFv4,LTjcTWqvsq3ju6pMGe9Cqb3scvQgECG81hRdgj5WO4s,AQACAAE/statistics/148/plot_link_length.png Best wishes, Arne PS: I also like it that you used freenet itself for hosting! -- Unpolitisch sein heißt politisch sein, ohne es zu merken. - Arne (http://draketo.de) signature.asc Description: This is a digitally signed message part. ___ Devl mailing list Devl@freenetproject.org https://emu.freenetproject.org/cgi-bin/mailman/listinfo/devl
Re: [freenet-dev] Pitch Black Attack - Analysis, Code, Etc.
On Sunday 27 Jan 2013 05:02:17 Michael Grube wrote: Hi everyone, Around this time last year I started on work to simulate the pitch black attack working against Oskar Sandberg's swapping algorithm that is implemented for use with darknet. The work is essentially incomplete, but I did enough to get an idea of how well Oskar's proposed solution to the Black Attack works. Hopefully the information that follows can provide some insight for anybody working on this problem. It looks like we have a good chance of using Oskar's original plan. Maybe even getting it published, with some help (carl might help even if you don't have time?). The code is messy, so I'm going to do a walkthrough of how exactly I ran the simulation. To start off, my code is available at http://github.com/mgrube/pbsim. Let's start. The first thing I did was create the small world network that is assumed in the darknet. The graph size can obviously be of any size, but in our experiment we'll make the network size 1000 nodes. This is pretty simple in python and can be accomplished with one line in the networkx library: You did check that there isn't a scalability issue? :) from pynetsim import * from networkx import * from pylab import * random_network = navigable_small_world_graph(1000, 4, 2, 1, 1).to_undirected() We've just made a Kleinberg small world graph of 1000 nodes with 4 nearest neighbors, 2 randomly chosen long distance connections, an exponent describing the probability of a connection(explicitly defined as 1/d for a Kleinberg graph) and specified one dimension. Library API looks nice. Is it too slow to simulate swapping on large networks? (100k nodes). There are various things it'd be interesting to try... Now we'll randomize the locations assigned to all of the nodes with the randomize function in pynetsim: randomize(random_network) To compare graphs with the same initial conditions, we're going to copy the graph... clean_swap_network = random_network.copy() attacked_network = random_network.copy() sandberg_solution_network = random_network.copy() Before we go any further, we should verify that the darknet swapping algorithm is implemented properly. In order for the swapping algorithm to be the most effective, it should occur about 2000N times, where N is the number of nodes in the graph. Let's do that: while i 2000: i += 1 swapiteration(clean_swap_network) swapIteration involves every node trying to swap once? Now it's time to stare at your computer while every node runs the swapping algorithm 2000 times. IIRC swapping doesn't scale (at least not linearly)... some of the papers talked about log^2(n) iterations? After you've done that, you can examine the link length distribution by using the hist function and the edges of the clean_swap_network: linklengths = list() for e in clean_swap_network.edges(): linklengths.append(abs(e[0][0] - e[1][0])) hist(linklengths, 100) I've taken a snapshot of the histogram that is generated from this: http://127.0.0.1:/CHK@YbRCKaxMhIxRgBpYIT2Ux4t-Pi01xxMu2XqWWvG2YY0,SWOn~fUZygCOzHNruIiw7eZEwqFDme9ZGTc4vdtgQFQ,AAMC--8/post_swapping.PNG Ok, so it looks like our swapping algorithm is properly implemented. Let's attack the network! attackers = list() pickmalnodes(attacked_network, attackers, 2) #We're picking 2 malicious nodes because that is the number chosen by the writers of the Pitch Black paper. attacksimulation(attacked_network, attackers) #We're using 2 nodes, each with 4 malicious locations. Maybe your code is easier to read than the paper ... Or maybe I was asleep when I read the paper... I wonder if it would be worth writing up the natural pitch black via churn evolution we saw in ~ 2008. Basically, when you have churn, newbies end up with the worst locations i.e. those furthest away from the main clusters. So even without an attack, the network locations become more and more clustered. We fixed it by periodic randomisation, which seemed to have relatively little cost - the nodes quickly got their old locations back, more or less. Another thing we want to look into is what the cost is of swapping (especially on a growing network, or even two networks merging) in terms of losing datastores due to locations changing. That might need more detailed simulations... We can see the aftermath by looking at a histogram of node locations. The randomize function uses a random function to assign each node a location, so first let's look at a histogram of locations before the attack: http://127.0.0.1:/CHK@ODZ1s5SDYrVvyNo0ONh4O9rtI~pcVmTSShh47UFPY5U,SKJfkX2eswHMrqidDWTUoZKGMaZ9yt0l6uLUZMmxOqk,AAMC--8/preattacklocations.PNG Suprisingly wide range of concentrations. The biasing locations for these attack nodes were: .6935 .1935 .9435 .4435 .4665 .9665 .7165 .2165 Our histogram of node locations now shows a disproportionate number of nodes
Re: [freenet-dev] Pitch Black Attack - Analysis, Code, Etc.
On Sunday 27 Jan 2013 14:06:08 Arne Babenhauserheide wrote: Hi Snark, Thank you for posting! Your analysis looks pretty good. Am Sonntag, 27. Januar 2013, 00:02:17 schrieb Michael Grube: Not bad! There is obviously still some influence but the location distribution has evened out noticeably. There is one down side to this solution, however, and that is that it appears to affect search performance. By how much, I am not sure, but our link length distribution is now looking less ideal: http://127.0.0.1:/CHK@TdODwHOdC9peiHYGtTxDa9yy9v0lXSHKWW4G7wM5-~A,OIy08YxNZdg4M3vpgm7wETOhUvU3RYFzrkJQ7No9poE,AAMC--8/deterioratinglinkdist.PNG What happens if you now apply normal swapping to this distribution? Does it get better or do we see a general problem of swapping? (in some tests while discussing probes, a swapping example I wrote worked well for some stuff, but broke down with certain configurations) The link length distribution could be a pretty big problem… Compare it with the real distribution: http://127.0.0.1:/USK@pxtehd-TmfJwyNUAW2Clk4pwv7Nshyg21NNfXcqzFv4,LTjcTWqvsq3ju6pMGe9Cqb3scvQgECG81hRdgj5WO4s,AQACAAE/statistics/148/plot_link_length.png I think this is backwards, can you show the ideal? Best wishes, Arne PS: I also like it that you used freenet itself for hosting! signature.asc Description: This is a digitally signed message part. ___ Devl mailing list Devl@freenetproject.org https://emu.freenetproject.org/cgi-bin/mailman/listinfo/devl