Mike Perry <[email protected]> writes: > Mike Perry: >> I spent some time trying to clean up proposal 247 based on everyone's >> comments, as well as based on my own thoughts. Please have a look if you >> commented on the original proposal, and complain if I've not taken your >> thoughts into account. > > I spent yet more time thinking about the new threat model and what the > adversary's expectation for how long they will have after the Sybil > compromise for the third guard completes before the second Guard rotates > away, and I have some awesome results. It turns out that if we make all > node rotation times fully independent, then the point at which the > adversary wins the Sybil attack on layer 3 will be uniformly distributed > with respect to the rotation period of the layer two guards. > > With the parameters I specified, this means that when you sum the total > remaining rotation expectations, the adversary will have at least a 19% > probability that they will have less than a day remaining before the > layer two guard changes on them after they win the Sybil, and at least a > 32% probability that they will have less than two days before this > happens. > > IMO, this is great news, as it shows that we can indeed force the > adversary to risk compromising/coercing nodes that end up having no > utility to them with high probability. > > I've added these results to Section 3.2.3 of the proposal in my remote, > and also added the full python script used to generate all tables as > Appendix A. > > Here's the new piece of Section 3.2.3: > https://gitweb.torproject.org/user/mikeperry/torspec.git/tree/proposals/247-hs-guard-discovery.txt?h=guard_discovery_dev#n331 >
Hm. how come the CDF is defined this way? Specifically, why do we do the following? For durations d greater than t days, we take the fraction of that rotation period's selection probability and multiply it by t/d and add it to the density. In other words: I'm more familiar with the CDF definition used in commit acf86d7 but changed afterwards. _______________________________________________ tor-dev mailing list [email protected] https://lists.torproject.org/cgi-bin/mailman/listinfo/tor-dev
