BTW (hypothetical) What happens if one group runs a good chunk of masternodes, say 51%. Would they have any advantage in breaking darksend anon (like running lots of tor nodes breaks tor anon)?
thx
At the actual rate owning the 51% of the MNs require an investmen of almost 1.5M$.
2250 MNs and DRK value being 3$ it would cost 3.3M$.
You see it gets harder and harder as the network keeps growning.
That is interesting point ... food for though; if you where the feds what would you do:
1. Buy 50%+ MN @ $2 million
2. Try and crack the encryption and spend $100+ millions and countless years if not decades?
It's not just 51% of the masternodes it would have to be a large majority of them, pushing the cost higher.
Masternode Snooping
When Darksend peers mix with each other they use a dedicated node, called a Masternode. This node in the present implementation is required to be able to see the inputs and outputs of the transactions to ensure that parties sign, otherwise the system will charge them collateral fees.
Peers mix with many different Masternodes in a row, known as rounds of anonymity in the client. To follow a transaction through the full process, a user must go through a series of malicious Masternodes. This process is random, so a bad actor would need to control many Masternodes in order to attack in this way.
The trade off is a sybil resistant system or one with more personal privacy from snooping Masternodes. But in the case where a Masternode is blinded, collateral protection cant be used. If a Masternode is blind to the submission of outputs and signing, by definition it would not know who to charge the collateral.
There are other options available, such as banning inputs of users that attempt to break the system. Something like this will have to be utilized in addition to a blinded setup to protect the system from abuse.
Source :
https://darkcointalk.org/threads/reply-to-kristovs-paper.2325/It was after the review of Kristov Atlas (many of those are now mitigated).