Calculating the chances of successfully spying on private send mixing, you would need far more than 50% of masternodes to hope to follow anything, especially at 8 rounds. I don't believe any one entity has more than 400 masternodes, but I can't prove anything. Even they can't follow 4-8 rounds of mixing (probably have no chance of following 2 rounds).
There is a chart somewhere that shows the % of Masternodes you would need to control to get a % chance at deanonymizing a private send. It's a bit old, it stops at 4000 masternodes, LOL, which we now have 4200+ but still, it shows how fruitless it is to try, and it would be a waste of money and resources for any large nefarious group to try.
now we can build new charts.
google sheet with the data
https://docs.google.com/a/masternode.me/spreadsheets/d/1hZ4BWlRgOmWSL336oBHmk0Mcl9AzdS6v6XsEDKlc5PQ/edit?usp=sharing
code
https://gist.github.com/moocowmoo/789f9e2e2bdddf0708a5d200f5c09c12
def capture_probability( n_full_set, n_capture_set, rounds):
return (n_capture_set / n_full_set) ** rounds
masternode_count = 4270
if __name__ == "__main__":
for percentage in range (5, 100, 5):
for rounds in range(1,9):
capture_set = masternode_count * float(percentage)/100
print "%s %s %s %.12f " % ( masternode_count, percentage, rounds, capture_probability(masternode_count, capture_set, rounds) * 1)
percent evil
rounds
mix percentage exposed
4270 5 1 0.050000000000
4270 5 2 0.002500000000
4270 5 3 0.000125000000
4270 5 4 0.000006250000
4270 5 5 0.000000312500
4270 5 6 0.000000015625
4270 5 7 0.000000000781
4270 5 8 0.000000000039
4270 10 1 0.100000000000
4270 10 2 0.010000000000
4270 10 3 0.001000000000
4270 10 4 0.000100000000
4270 10 5 0.000010000000
4270 10 6 0.000001000000
4270 10 7 0.000000100000
4270 10 8 0.000000010000
4270 15 1 0.150000000000
4270 15 2 0.022500000000
4270 15 3 0.003375000000
4270 15 4 0.000506250000
4270 15 5 0.000075937500
4270 15 6 0.000011390625
4270 15 7 0.000001708594
4270 15 8 0.000000256289
4270 20 1 0.200000000000
4270 20 2 0.040000000000
4270 20 3 0.008000000000
4270 20 4 0.001600000000
4270 20 5 0.000320000000
4270 20 6 0.000064000000
4270 20 7 0.000012800000
4270 20 8 0.000002560000
4270 25 1 0.250000000000
4270 25 2 0.062500000000
4270 25 3 0.015625000000
4270 25 4 0.003906250000
4270 25 5 0.000976562500
4270 25 6 0.000244140625
4270 25 7 0.000061035156
4270 25 8 0.000015258789
4270 30 1 0.300000000000
4270 30 2 0.090000000000
4270 30 3 0.027000000000
4270 30 4 0.008100000000
4270 30 5 0.002430000000
4270 30 6 0.000729000000
4270 30 7 0.000218700000
4270 30 8 0.000065610000
4270 35 1 0.350000000000
4270 35 2 0.122500000000
4270 35 3 0.042875000000
4270 35 4 0.015006250000
4270 35 5 0.005252187500
4270 35 6 0.001838265625
4270 35 7 0.000643392969
4270 35 8 0.000225187539
4270 40 1 0.400000000000
4270 40 2 0.160000000000
4270 40 3 0.064000000000
4270 40 4 0.025600000000
4270 40 5 0.010240000000
4270 40 6 0.004096000000
4270 40 7 0.001638400000
4270 40 8 0.000655360000
4270 45 1 0.450000000000
4270 45 2 0.202500000000
4270 45 3 0.091125000000
4270 45 4 0.041006250000
4270 45 5 0.018452812500
4270 45 6 0.008303765625
4270 45 7 0.003736694531
4270 45 8 0.001681512539
4270 50 1 0.500000000000
4270 50 2 0.250000000000
4270 50 3 0.125000000000
4270 50 4 0.062500000000
4270 50 5 0.031250000000
4270 50 6 0.015625000000
4270 50 7 0.007812500000
4270 50 8 0.003906250000
4270 55 1 0.550000000000
4270 55 2 0.302500000000
4270 55 3 0.166375000000
4270 55 4 0.091506250000
4270 55 5 0.050328437500
4270 55 6 0.027680640625
4270 55 7 0.015224352344
4270 55 8 0.008373393789
4270 60 1 0.600000000000
4270 60 2 0.360000000000
4270 60 3 0.216000000000
4270 60 4 0.129600000000
4270 60 5 0.077760000000
4270 60 6 0.046656000000
4270 60 7 0.027993600000
4270 60 8 0.016796160000
4270 65 1 0.650000000000
4270 65 2 0.422500000000
4270 65 3 0.274625000000
4270 65 4 0.178506250000
4270 65 5 0.116029062500
4270 65 6 0.075418890625
4270 65 7 0.049022278906
4270 65 8 0.031864481289
4270 70 1 0.700000000000
4270 70 2 0.490000000000
4270 70 3 0.343000000000
4270 70 4 0.240100000000
4270 70 5 0.168070000000
4270 70 6 0.117649000000
4270 70 7 0.082354300000
4270 70 8 0.057648010000
4270 75 1 0.750000000000
4270 75 2 0.562500000000
4270 75 3 0.421875000000
4270 75 4 0.316406250000
4270 75 5 0.237304687500
4270 75 6 0.177978515625
4270 75 7 0.133483886719
4270 75 8 0.100112915039
4270 80 1 0.800000000000
4270 80 2 0.640000000000
4270 80 3 0.512000000000
4270 80 4 0.409600000000
4270 80 5 0.327680000000
4270 80 6 0.262144000000
4270 80 7 0.209715200000
4270 80 8 0.167772160000
4270 85 1 0.850000000000
4270 85 2 0.722500000000
4270 85 3 0.614125000000
4270 85 4 0.522006250000
4270 85 5 0.443705312500
4270 85 6 0.377149515625
4270 85 7 0.320577088281
4270 85 8 0.272490525039
4270 90 1 0.900000000000
4270 90 2 0.810000000000
4270 90 3 0.729000000000
4270 90 4 0.656100000000
4270 90 5 0.590490000000
4270 90 6 0.531441000000
4270 90 7 0.478296900000
4270 90 8 0.430467210000
4270 95 1 0.950000000000
4270 95 2 0.902500000000
4270 95 3 0.857375000000
4270 95 4 0.814506250000
4270 95 5 0.773780937500
4270 95 6 0.735091890625
4270 95 7 0.698337296094
4270 95 8 0.663420431289