Bitcoin Forum

Quick question: can or cannot a powerful actor, like an opressive government compromise bitcoin? For example, run multiple rogue bitcoin full nodes and modifying source code according to their best interest. What is the worst that can happen?

Thanks.

Nothing

How can a node have a colour anyway?

http://grammarist.com/spelling/rogue-rouge/

If the government run a billion nodes, far more than the amount of nodes currently running and all those nodes tried to block a payment then what happens? Have a little think about it. Those nodes can't influence the miners and the legitimate nodes. All that would happen is the government nodes would be changing rules but those rules would just be for themselves, the government would end up with an odd alternative bitcoin network that means nothing to the outside world.

The only time they can influence the real bitcoin network is if they forced every bitcoin user to use their version of the code as a node. Of course this is an exponentially harder problem than simply having more mining power than the network.

So the nodes are not an issue. Only having majority control of the miners matters. The government can own 99.999% of all the nodes, but because no real commerce will be done with those nodes it does not matter.

the worst case is that the USG or some other large-scale actor has ASICs that can beat the shit out of everything created publicly thus far. in this case they can rewrite, i.e. spoof, the entire blockchain since the last checkpoint. however, this is highly unlikely and would blow their cover since there is no plausibly deniable story for what happened besides "we decided to take over your chain, dawg". i know some ppl have a distaste for checkpoints, but i think they are a good idea.

as i stated above, such an attack would be rather overt and would likely tip the hand of an attacker. once you know someone knows, you know you need to adjust your behavior (hawthorne effect). lesser attacks would be 51% attacks but these suffer from the same hawthorne effect mechanism i just referenced.

overall, the system is quite secure unless a large group with advanced crypto knowledge, tons of money and serious hw chops were to openly attempt to shut it down.

From a related thread:

Oh wow that is an interesting attack. Run so many nodes as to isolate legitimate ones.

I wonder what possible solutions exit?

Running lots of nodes is not an effective attack vector if you are looking to disrupt the workings of the network.

Running a significant portion of nodes could be used, however, to unmask the identity of someone behind a transaction. If a malicious entity is connected to every node it is easy to figure out who is who. The first node to propagate a transaction is presumably one of the parties involved in the transaction... thus you now know the origin IP of the transaction.