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Has a cryptocurrency network ever been fully DDoSed so that the blockchain did not advance during the attack?
If so, which one and how?
Have network DDoS attacks ever been successful on any coin?
Answers
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This is more or less impossible, since you don't know where the miners are. Attacking the major mining pools is feasible, though they deploy some anti-DDoS measures. But even when such an attack would succeed, there still are people non-affected (eg. running behind NAT) and running the *coin network like if nothing happened.
The only issue that I can notice there is that the difficulty for getting a new block would be too high, so that the blocks would be mined much slower.
1@Gracchus Yes, of course, those centralized services are vulnerable places (cf. DDoSes at major bitcoin exchanges). NAT protects from DDoS, since you don't publish your IP address, so that nobody knows, that there is a node behind this NAT, of course except from nodes you are connected to (unless they choose to publish it, which is a nonsense). I'm talking about a full NAT and not about a situation when you have an open TCP port. I also believe that p2pool users shouldn't be affected, since it's a decentralized protocol. – czaks – 2014-04-06T00:59:32.553
Would be really difficult to DDOS a whole coin's network unless it were a coin still in infancy. 51% attacks have happened (intentional or not) and do stop the chain from advancing. Don't know if "dust spam" attacks (flooding the network with various ultra-tiny transactions transactions of real worth take a lot to get confirmed) have succeeded so far... – Joe Pineda – 2014-03-16T14:29:14.487
Because, except at a coin's release date, you don't know the IP addresses of most of miners to effectively DDOS them out- with just one miner the blockchain would go on save it'd be now at the mercy of that miner (51% attack). – Joe Pineda – 2014-03-17T17:44:34.270
1Another type of DDOS attack I just thought of would be to pollute the network by using plenty of modified clients that connects to the usual port but emit badly formatted packages - or randomly corrupts the transactions it relays. Don't know how feasible/effective it'd be, though... – Joe Pineda – 2014-03-17T17:47:01.037
@JoePineda, What do you mean by "dust spam"? – Pacerier – 2014-05-23T15:40:35.647
@Pacerier Please have a look at http://bitcoin.stackexchange.com/questions/10986/what-is-meant-by-bitcoin-dust
– Joe Pineda – 2014-05-30T10:48:44.257