Ethereum Classic

Ethereum Classic is the continuation of the original Ethereum blockchain, preserving the chain history that existed before the July 2016 hard fork. That fork was carried out in response to the DAO hack, in which a large amount of ether was drained from a smart contract, and it reversed those transactions on the chain that became today's Ethereum. A portion of the community rejected the reversal on the principle that the ledger should not be altered, and continued running the unchanged chain as Ethereum Classic.

The network shares Ethereum's genesis date of 30 July 2015 and its early technical design, including the Ethereum Virtual Machine, so smart contracts written for Ethereum can generally be deployed to it.

Consensus and supply

Ethereum Classic uses proof of work with the Ethash algorithm, which is the mechanism Ethereum itself abandoned in 2022 when it moved to proof of stake. That transition made Ethereum Classic one of the larger remaining destinations for GPU mining hardware. Miners compete to produce blocks and receive newly issued ETC as a reward.

Unlike Ethereum, Ethereum Classic adopted a capped monetary policy. Its maximum supply is approximately 210.7 million ETC, with the block reward reduced by twenty percent roughly every five million blocks under a schedule known as the fifth exponential subsidy reduction. Current circulating supply is around 158 million.

Position today

The network positions itself around immutability and a fixed supply rather than around rapid feature development. It suffered several 51 percent attacks in 2019 and 2020, which prompted changes to how exchanges handle confirmations and led to work on strengthening security. Development continues at a slower pace than on Ethereum, with the chain periodically adopting compatible upgrades to stay aligned with the Ethereum Virtual Machine.