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The Ethereum network is currently undergoing a DoS attack

blog.ethereum.org

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Re: The Ethereum network is currently undergoing a DoS attack

#31

Post by RexetBlell »

cryptarch wrote: post #25

Could individual miners change the cost they charge for individual opcodes, or perhaps even disable specific opcodes alltogether?

The developers were thinking of doing this at the beginning but decided against it.

Currently, when you send a transaction, the transaction includes a gas price that you are willing to pay for a unit of gas. The miners then decide if they want to mine your transaction, or not. Each opcode in the Ethereum Virtual Machine requires a different amount of gas, which is hard coded (look at this spreadsheet: https://docs.google.com/spreadsheets/d/1m89CVujrQe5LAFJ8-YAU... the opcode that is causing trouble today is EXTCODESIZE which has a gas cost of 20, which is apparently too low).

Initially, there were ideas where you could specify in the transaction the gas price you are willing to pay for each opcode. But this would make transactions very large (in terms of bytes).

Re: The Ethereum network is currently undergoing a DoS attack

#32

Post by Animats »

Etherium is a first cut at a hard problem. The "smart contracts" problem is interesting, but after the DAO debacle, it's clear that smart contracts shouldn't be executable programs. It's too hard to predict their behavior, and that's very bad when they're connected directly to money. Some human-readable declarative notation is needed. I've suggested decision tables. Dealers need enough expressive power to handle all the usual financial instruments, but don't need or want Turing completeness.

Another advantage of a declarative notation is that compute time tends to be bounded by a fairly low bound. That would put a lid on problems like this new one, where the little programs are chewing up too much time.

We may see some smart contracts system with a better notation in the derivatives business. It doesn't need to be a currency, just a blockchain with enough identified independent players to prevent tampering. The need for "mining" comes from the desire for anonymity; it's not inherent in smart contracts.

Re: The Ethereum network is currently undergoing a DoS attack

#33

Post by valarauca1 »

zorked wrote: post #22
fragsworth wrote: post #8

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…

Is there another angle? E.g. can the attacker have precomputed the results of those operations and now he can mine faster than anybody else or something like that?

Yes you can game the network by writing your own Ethereum Mining Client. Introducing a ton of code. Selectively ignoring code. BUT this isn't smart. You are devaluing the currency you are deriving profit hurting your profit margin.

Furthermore you need to maintain plausible deniability. THIS IS HARD. If Ethereum catches you, they'll just hard fork. So your average blocked claims can't change by a large amount. So in reality you already need to 1st/2nd sigma miner, then increase your profits by maybe 20-30%. This is a lot of risk, and a ton of work.

Most likely it is just somebody doing it for the lulz

Re: The Ethereum network is currently undergoing a DoS attack

#34

Post by TD-Linux »

zorked wrote: post #22
fragsworth wrote: post #8

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…

Is there another angle? E.g. can the attacker have precomputed the results of those operations and now he can mine faster than anybody else or something like that?

Yes, it's possible to do that. I'm not sure if the current miner is, though.

Re: The Ethereum network is currently undergoing a DoS attack

#35

Post by TD-Linux »

cryptarch wrote: post #25

Could individual miners change the cost they charge for individual opcodes, or perhaps even disable specific opcodes alltogether?

Yes, but if some other miner decides to actually build on top of the other block, the miner that chooses not to will get orphaned and lose their block reward.

In addition, the cost of the expensive blocks is a burden on the entire network, not just the miners.

Bitcoin has a soft fork process (BIP9) where a rule can be enforced among all nodes at the same time. Of course, it is necessarily slow to activate and currently requires 95% of miners to signal support to minimize the number of blocks produced using the old rules.

Re: The Ethereum network is currently undergoing a DoS attack

#36

Post by RexetBlell »

Karellen wrote: post #14
ForHackernews wrote: post #2

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…

The transactions are verified by all full nodes (which are basically all users).

Re: The Ethereum network is currently undergoing a DoS attack

#37

Post by [deleted] »

komaromy wrote: post #29
paavokoya wrote: post #28

Earlier quoted context omitted.

Just means the market needs to raise the prices. In bitcoin this is similar to raising transaction fees to add a disincentive for DDOS attacks. Right now, it seems ethereum is just an almost-free VPS service and people are surprised that actors are taking advantage of it.

> almost-free VPS service I guess, if most VPS services cost >$5/minute: https://www.reddit.com/r/ethtrader/comments/53xt58/daily_dis...

[deleted]

Re: The Ethereum network is currently undergoing a DoS attack

#38

Post by Tinyyy »

aminok wrote: post #24
soared wrote: post #10

Who benefits from this?

Organisations that want to maintain control over society. Case in point is the International Cyber Security Protection Alliance: https://www.reddit.com/r/Bitcoin/comments/1h43ez/chilling_ar... . This organization represents major financial firms, including Visa Europe, and law enforcement agencies, including the City of London Police and Europol, and had a 2 page article appearing in the 2013 G8 trade magazine callin…

>People who run this organization appear to be ruthless and amoral

...

>Going as far as talking about a DDOS attack on Twitter

Also, that G8 article you linked has a full page MTGOX ad on page 8. Kinda ironic huh?

Okay, enough with the low hanging fruits, now some serious stuff.

I don't see how Bitcoin enthusiasts can trivially brush off the criminal activities connected to Bitcoin. The public at large doesn't care about your shiny little toy - but they do if it's used by criminals. The article specifically mentions child pornography. Now how can CP be distributed? Tor and hidden services. But how is someone going to pay / profit from it? There was no easy solution - then comes Bitcoin, and suddenly people can be absolutely untraceable on the internet. You cannot simply ignore this. You have to acknowledge it, and then a) provide some form of solution (kinda contradicts its principles) or b) argue that it isn't as important compared to potential benefits of Bitcoin.

Re: The Ethereum network is currently undergoing a DoS attack

#39

Post by deegles »

valarauca1 wrote: post #33
zorked wrote: post #22

Earlier quoted context omitted.

Is there another angle? E.g. can the attacker have precomputed the results of those operations and now he can mine faster than anybody else or something like that?

Yes you can game the network by writing your own Ethereum Mining Client. Introducing a ton of code. Selectively ignoring code. BUT this isn't smart. You are devaluing the currency you are deriving profit hurting your profit margin. Furthermore you need to maintain plausible deniability. THIS IS HARD. If Ethereum catches you, they'll just hard fork. So your average blocked claims can't change by a large amount. So in…

I'm disappointed that the devs established the precedent that if things go south they'll hard-fork. It reduces the incentive to avoid risky behavior. Having a centralized roll-back/bailout authority is what led to too-big-to-fail banks.

Re: The Ethereum network is currently undergoing a DoS attack

#40

Post by makomk »

paavokoya wrote: post #28
fragsworth wrote: post #8

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…

Just means the market needs to raise the prices. In bitcoin this is similar to raising transaction fees to add a disincentive for DDOS attacks. Right now, it seems ethereum is just an almost-free VPS service and people are surprised that actors are taking advantage of it.

This isn't quite sufficient, because the prices are set by miners but the transactions have to be processed by every single full node in existence. That's why Bitcoin has a hard upper limit on the complexity of processing any given block.
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