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The Ethereum network is currently undergoing a DoS attack

blog.ethereum.org

11–20 of 45 posts

Re: The Ethereum network is currently undergoing a DoS attack

#11

Isn't this the kind of thing that a decentralized network should be resilient against? Maybe I just don't understand blockchains.

The network protocol agrees that operation F is priced at X, with an understanding that operation F costs Y. The decentralized nature is exactly what makes it hard to suddenly and unilaterally make a policy change of "F is now forbidden, or F now costs 100x more". This is a good thing. It means that people can't make sudden unilateral changes :)

Re: The Ethereum network is currently undergoing a DoS attack

#12

My understanding is it works like this in Ethereum: The miners can run any arbitrary code ("a contract") that you write, and this code is verifiable and trusted by everyone once it's been uploaded to the blockchain. The contracts can read/write arbitrary things in the blockchain and send coins to anyone you want, determined by the code you write. There's a "gas price" that you have to pay for each operation you tell…

Sounds right. In Bitcoin, there are also some opcodes that are more expensive than others (hashing) which have been limited to a certain count per block.

Re: The Ethereum network is currently undergoing a DoS attack

#13

Isn't this the kind of thing that a decentralized network should be resilient against? Maybe I just don't understand blockchains.

Me neither. I thought the same. Is there some centralized single point of failure? That would invalidate the premise of decentralization surely?

Re: The Ethereum network is currently undergoing a DoS attack

#14

Isn't this the kind of thing that a decentralized network should be resilient against? Maybe I just don't understand blockchains.

From the article:

> miners and nodes need to spend a very long time processing some blocks. This is due to the EXTCODESIZE opcode, which has a fairly low gasprice but which requires nodes to read state information from disk;

AIUI, the data in the blockchain isn't just "data". It's actually small bits of code that execute inside a VM, which each node needs to execute in order to "understand" the blockchain. "EXTCODESIZE" would be one of the instructions in this particular VM.

I think that most blockchains either have a complexity limit per record/transaction, or have a complexity "cost", so that complex code is more costly to insert into the blockchain.

However, in this case, it sounds like someone has figured out how to insert some code that is actually more complex than the complexity-measuring code thinks it is, and is therefore causing all miners (all users?) to perform higher-than-expected amounts of computation to parse the blockchain, to the point where they can't keep up with the network.

(Corrections welcome)

Re: The Ethereum network is currently undergoing a DoS attack

#15
post #10

Who benefits from this?

The crypto-community is a pie whose size isn't changing much. Coin prices fluctuate as investors move money from one coin to another, which causes price fluctuations. Attacks like this one which make ethereum look bad are beneficial to those other coins, who will expect prices to rise as a result of people selling their ETH out of fear.

Re: The Ethereum network is currently undergoing a DoS attack

#16

Isn't this the kind of thing that a decentralized network should be resilient against? Maybe I just don't understand blockchains.

From the article: > miners and nodes need to spend a very long time processing some blocks. This is due to the EXTCODESIZE opcode, which has a fairly low gasprice but which requires nodes to read state information from disk; AIUI, the data in the blockchain isn't just "data". It's actually small bits of code that execute inside a VM, which each node needs to execute in order to "understand" the blockchain. "EXTCODESI…

This is exactly correct.

Re: The Ethereum network is currently undergoing a DoS attack

#19
post #4

Earlier quoted context omitted.

It's not a network flooding attack, it's a "please each of you do this time-wasting thing" attack.

But that's also a DoS attack. If they're doing the time-wasting thing, they can't do other things... Denying service.

Sure but I think the person you replied to thinks the person the person you replied to replied to thinks it's a network attack because s/he said "shouldn't decentralized networks be resilient against this".

Re: The Ethereum network is currently undergoing a DoS attack

#20

Isn't this the kind of thing that a decentralized network should be resilient against? Maybe I just don't understand blockchains.

Decentralized networks benefit from no single entity being a bottle neck on connections. All a conventional DDOS does is slow down that single entity- here someone is employing the network to slow down most entities which uphold the network, achieving a very similar result.
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