Dear Cypherpunks community, I came across a post on the Whonix forum recently. Since I am also interested in this question I copied it here: https://forums.whonix.org/t/math-behind-honest-tor-nodes/12464 http://forums.dds6qkxpwdeubwucdiaord2xgbbeyds25rbsgr73tbfpqpt4a6vjwsyd.onion... The question (edited): How can I calculate how much impact X honest Tor relays have? Is it better to calculate with bandwidth consumed (250Gbps), despite the number of relays (~7000)? Basically, I want to get the mathematical equation to this statement: I run X Tor relays at Y Mb/s each and by doing so I secure Z % of the Tor network! Starting thoughts: - Each “normal” route has three nodes involved: Guard, Middle, Exit - I am aware of guard pinning and vanguard protection for middle relay pinning - Maybe it is easier to assume an infinite usage time of the network to eliminate guard and vanguard pinning - I guess the best is to assume a scenario with 1%, 5%, 10%, etc. dishonest relays My take on this: Tor has approximately 7000 relays. If I consider a number of 5% malicious relays, this would be: 350 My calculation: (1/(7000/350))*(1/(7000/349))*(1/(7000/348)) = 0.000123931 = 0.0123931% 1) Is my approach correct? 2) Not every relay has the same bandwidth. How could I change the calculation to make it more realistic? 3) How can I add the effect of guard fixation? 4) How can I include the effect of mid-node fixation by the vanguard? I would love to hear your thoughts about it and a concrete math equation would be amazing.