Dear Ilshat, They are nice results. What 40% on-off attack means? Best, Leo El mar, 18-08-2015 a las 17:24 +0500, Ilshat Shakirov escribió: > Hello!, > > Here is small status update. > I've implemented new types of attack for malicious peers: > -persistent attack > -on-off attack > -selective attack > -bad-mouth attacj (for strpe-ds only) > > Also, I've added new option --checkall for STrPe trusted peers. If > this option is enablde, then TP sends every received chunk to > splitter to check. > > Here is some tests I performed for STrPe mechanism: > Persistent attack (with checkall option) : https://docs.google.com/sp > readsheets/d/1iNva1mvO9NETj8fJ9oZpy1VhAUYxJi4K7gUojqzSEqI/edit > On-off attack (40%) : https://docs.google.com/spreadsheets/d/1-sLkrjd > NQHx-jXxWeVYz4pmnd6qgC1D3MuVnbhQ4lYE/edit?usp=sharing > > For each configuration Ive performed 5 experiments, on last tab the > result table is presented. > > I've made next observations (for STrPe): > - there is need to increase splitter's buffer, since it have to check > chunks which can be deleted from its buffer. I've performed tests > with --buffer_size 1024 (256 by default). I think that buffer should > smth like 4 * team_size. > - with check all option number of TP doesnt affect speed of expulsion > mal. peers (in case of persistent attack). Every mal. peer is > excluding for 1 splitter round in average. > - in on-off attack number of TP affects on speed of excluding peers. > So, more TPs - more chances to send posioned chunks to TP. > - there is very small affect on buffer correctness for all the team. > Average for the team is between 0.95 and 1. > > Also, here is my testing plan : https://docs.google.com/document/d/13 > oSUgkRrmUh8nM3mMe5FEmwBlSfrxs0NXkei0JVubBo/edit?usp=sharing > > Currently, Im performing tests for STrPe-DS mechanism (according to > my test plan). > > Thanks. > > 2015-08-14 2:03 GMT+05:00 Ilshat Shakirov <[email protected]>: > > Hello!, > > > > Here is two raw data sets with result data from experiments with > > STrPe and STrPe-DS: > > > > STrPe: https://docs.google.com/spreadsheets/d/13xzEwQKbB58p0K8VyQjv > > ez2L-QABP_ouelbqmWMSE7w/edit#gid=1026220953 > > STrPe-DS: https://docs.google.com/spreadsheets/d/1YZnLaWrjAJRgXZ2LQ > > rHhgewOnzL1Fm073ix6dULmwpc/edit#gid=1531244678 > > > > As you can see in STrPe number of TP affects on speed of expulsion > > mal. peers. It happens because TP selects next chunk to check > > randomly from its stream of chunks. Resp. if we have more TP then > > it will take less number of rounds to expel all TP. > > You can check it in code here: > > https://github.com/P2PSP/p2psp/blob/cis/src/trusted_peer.py#L55 > > > > Also, you can see that in STrPe-DS if we have more mal. peers, we > > have more rounds to expel all mal. peers. It happens because > > including new mal. peers take 0.5 - 1 round, and resp. we have more > > rounds to include all mal. peers to the team. In the simple > > persistent attack mal. peers excluding almost at the same time they > > sended poisoned chunk to TP. > > > > > Why a TP does not check every chunk? > > > In a persistent attack, peers will be detected directly. > > > > > > > Because it can reduce the performance of TP and the system (I > > think) > > > > > Again, for persisten attack this is true, but not for the more > > > sophisticated ones. > > What kinds of attack should I perform? > > > > Also, I think I know how to compromise Third Trusted Party (and > > resp. perform selective attack) for only log(n) time. > > Attacker should perform attack on the half of the team. If mal. > > peer was excluded, then in given half exists TP. Then this half > > divide to new 2 halfs and so on. So, we can find all the TPs in > > O(log2(n)) time. > > > > Thanks! > > > > > > 2015-08-12 15:43 GMT+05:00 L.G.Casado <[email protected]>: > > > Hello, > > > > > > > > > El mié, 12-08-2015 a las 15:27 +0500, Ilshat Shakirov escribió: > > > > Hello, > > > > > > > > > N-1, is set because there is one Trusted peer, does it? > > > > Yes, because trusted peer doesnt check itself. > > > > > > > > > How is set X, random check yes/no? > > > > > > > > > I think yes. In the first impl of STrPe trusted peers checked > > > > every 255 received chunk. > > > > > > > Why a TP does not check every chunk? > > > In a persistent attack, peers will be detected directly. > > > > > > The random check could be seen as malicious peer performing a > > > kind of selective attack. > > > > > > > About current progress: > > > > I've found a small bug in the initialization of big teams (i.e. > > > > 100 peers) with enabled STrPe-DS. In 2-3% of cases peer hangs > > > > up and do nothing. > > > Then, they should be expeled soon. > > > > > > > Also, Ive prepared a raw data from STrPe experiments (Ive > > > > performed experiments with 100 peers, 1-2-4-8 trusted, and 10 > > > > -25 malicious). And since trusted peers in STrPe checks chunks > > > > randomly from all the peers in the team, it can take long time > > > > to expel all the malicious peers. It happens because TP selects > > > > chunk to check from all stream, although it should select > > > > chunks from each peer. > > > I think to check randomly has no sense if trusted peer is in > > > system without resources limitations, which should be the case. > > > > > > > If we implement this, then Juan will be right and number of TPs > > > > in the team won't have impact on mal. peer expulsion. Now, if > > > > we have more TP, we have more chances, that TP will check chunk > > > > from mal. peers and will exclude it. > > > Yes, checking them all, just on TP is enough for persistent > > > attack, but it is not the case for other attacks. > > > > > > > Also, STrPe-DS don't have such problem, because I've > > > > implemented next logic:Every S seconds splitter selects new > > > > peer from all the team and TP from trusted peers and do 2 > > > > requests to gather complains from the team. > > > > So, mal. peers will be excluded almost in the same time they ve > > > > sended poisoned chunks to TP. > > > > > > > Again, for persisten attack this is true, but not for the more > > > sophisticated ones. > > > > Thanks! > > > > > > > Best, > > > > > > Leo > > > > > > > 2015-08-12 15:08 GMT+05:00 L.G.Casado <[email protected]>: > > > > > Dear Ilshat, > > > > > > > > > > El mié, 12-08-2015 a las 12:04 +0200, L.G.Casado escribió: > > > > > > BC = 1 - M / (N - 1 + 1) = 1 - M / N, > > > > > Sorry, the formula was fine: > > > > > > > > > > (N-M)/N= 1-M/N > > > > > > > > > > Please, answer the other questions. > > > > > > > > > > Thanks, > > > > > > > > > > Leo > > > > > > >
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