Hello!,
> They are nice results. > Thanks! > What 40% on-off attack means? > In 40% of cases peer sends poisoned chunk instead of correct chunk. 2015-08-18 17:34 GMT+05:00 L.G.Casado <[email protected]>: > 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/spreadsheets/d/1iNva1mvO9NETj8fJ9oZpy1VhAUYxJi4K7gUojqzSEqI/edit > On-off attack (40%) : > https://docs.google.com/spreadsheets/d/1-sLkrjdNQHx-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/13oSUgkRrmUh8nM3mMe5FEmwBlSfrxs0NXkei0JVubBo/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/13xzEwQKbB58p0K8VyQjvez2L-QABP_ouelbqmWMSE7w/edit#gid=1026220953 > STrPe-DS: > https://docs.google.com/spreadsheets/d/1YZnLaWrjAJRgXZ2LQrHhgewOnzL1Fm073ix6dULmwpc/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 > > > > > > >
-- Mailing list: https://launchpad.net/~p2psp Post to : [email protected] Unsubscribe : https://launchpad.net/~p2psp More help : https://help.launchpad.net/ListHelp
