Ethereum Classic Labs Increase Resistance To 51% Attacks
The recent attack reorganized more than 7,000 blocks, which ,to put in perspective is appropriately 2 days worth of mining. The previous attacks reorganized 3,693 and 4,000 blocks. Eth Classic is a proof-of-work (PoW) blockchain, and when a 51% attack happens on this type of consensus mechanism, it means that a malicious actor is able to take control of the majority of the network’s hash rate, enabling the reorganization of transactions.
Ethereum Classic’s community is considering several options for increasing resistance to 51% attacks, which should be implemented within the next 3 months. While these alone will not prevent any future attacks, they would be part of a range of upgrades on Eth Classic ,
.One option is PIRLGUARD, developed, and proposed by the Pirl community . ECIP-1092 states that instead of automatically synchronizing with any offline pre-mined chain branch, the new protocol should require peer proposing the longer and heavier chain to mine a number of penalty blocks. The number of penalty blocks depends on the number of the original blocks that would be reverted if the chain reorganized and synchronized to the proposed reorganization.
Another one of the forwarded proposals is enhancing the chain with check pointing and time stamping . This proposal would employ an external set of parties that securely run an assisting service that guarantees the ledger’s properties.
There are also a number of other proposals currently under development for more long-term fixes, all of which require community consensus in order for them to be implemented.