In a Core Devs assembly on Friday, Ethereum (ETH) builders mentioned potential measures that might be taken to stop profitable 51% assaults from oc
In a Core Devs assembly on Friday, Ethereum (ETH) builders mentioned potential measures that might be taken to stop profitable 51% assaults from occurring.
The dialogue was impressed by this week’s 51% assaults on Ethereum Traditional (ETC) — a community that represents the unique state of Ethereum the place the implications of the DAO hack in 2016 weren’t reverted. The unique assault, which occurred between July 31 and Aug. 1, was revealed to be a rigorously orchestrated try at a double-spend that netted over $5 million in ETC to the attacker for a $200,000 funding in hashpower.
In the course of the name, Ethereum shopper builders mentioned if they need to take further measures in opposition to these assaults and the way such measures ought to be carried out.
Reducing the reorg cap
A possible safety in opposition to chain reorganization is establishing checkpoints at a node stage which might set the historical past of the blockchain in stone after that time. Any proposed blockchain modifications past this checkpoint would thus be rejected by nodes.
Chain reorganizations depend on mining an alternate model of the blockchain with the next quantity of hashpower than the commonly-accepted model. Because of the guidelines of Nakamoto consensus, the chain with the next gathered proof-of-work would mechanically change the unique when printed to nodes.
Peter Szilagyi, developer of the Geth shopper, mentioned that the software program already rejects reorganizations deeper than 90,000 blocks, or two weeks. That is nevertheless a lot greater than the efficient reorg that occurred in ETC of about 4,000 blocks.
Whereas reducing this threshold might assist defend from comparable assaults, Alexey Akhunov of OpenEthereum famous that caps set too low can have unexpected penalties.
Measures could also be ineffective
The depth of the ETC reorg was dictated partly by a historical past of earlier assaults. These led exchanges to massively elevate the affirmation threshold to simply accept deposits.
Szilagyi mentioned that for Ethereum, there is no such thing as a want for hundreds of blocks. Decentralized exchanges might be gamed by censoring transactions and maximizing the hacker’s buying and selling good points with reorganizations of only a few blocks. Setting a checkpoint cap that low could end in vital usability points. He added:
“I simply needed to spotlight that after you settle for that there are 51% assaults on the community, a variety of issues begin breaking, as a result of a variety of issues depend on the belief that you simply can’t have deep reorgs.”
Tim Beiko, a developer at Ethereum improvement firm PegaSys, famous that ETC’s case could also be totally different. As a consequence of it being a a lot smaller and fewer helpful chain, it’s straightforward to assemble the required hashpower to finish a 51% assault by one thing like Nicehash. This, to him, “is an even bigger concern than no matter purchasers implement by checkpoints.”
In the long run, builders agreed to debate the problems extra and assume by potential enhancements to Ethereum’s resilience.