On Monday 17 December 2001 05:13 pm, you wrote: > Another question to bore you guys ;) > > I understand a message with ahops-to-live value of 1 is sometimes still > forwarded on, to reduce the information an attacker could get out of it. > What I don't understand, is what information could be learned from the > fact thatsomeone will be the last node reached on the path. > > For example, why would I want to know that some node at the end of the > path replies with a Reply.NotFound message? What kind of discriminating > information could I get from that?
It is for malicious ADJACENT nodes. If node A has a direct connection to node B, node A can find out if the data exists on that node by requesting the file with a htl of 1. This knowlege can be bad, as Sebastian pointed out. With the certain probibility of forwarding HTL 1 requests, the act of requesting the data can put the data on the node. This has the benefit of mirroring the data and improving legal arguments. Actually, why isn't the HTL concept abonded and replaced with a high certain probability? This way nodes can't choose a HTL that they can use for gaining data from freenet. Here is a table of probabilities and and average hops: 50% 1 hop 70% 1.9 hops 80% 3.1 hops 90% 6.6 hops 95% 13.5 hops 96% 17.0 hops 97% 22.8 hops 98% 34.3 hops 99% 68.0 hops And if you want to know how I got theese values, here's the formula: 1. probability^hops=0.5 (0.5=50%) 2. log(probability^hops)=hops*log(probability)=log(0.5) 3. hops=log(0.5)/log(probability) If a node removes the request by a probabilistic chance, it could return with two messages, one saying the probabilty finally told it to stop searching and another to tell that it could not find a closer node. If the probability did not fail, nodes could then continue the search with their next-closest node. Scott Young _______________________________________________ freenet-tech mailing list [EMAIL PROTECTED] http://lists.freenetproject.org/mailman/listinfo/tech
