The Ethereum hard fork at block 1,920,000 rewrites state and produces Ethereum Classic

JUL 20 2016 · 12:10

Video: Ethereum, A Classic Tale of Two Chains Date: 2016-07-20 · Type: ethereum · Tags: fork, ethereum-classic, code-is-law, governance, immutability, 2016 A one-time social slashing, executed by majority and contested by a minority that refused to disappear At block 1,920,000 on July 20 2016, the Ethereum community executed a hard fork that effectively rolled back the DAO hack — moving the drained ETH to a recovery contract and erasing the attacker's gains. The Carbon Vote, running May through July, showed roughly 87% of votes in favor, but on strikingly low participation: single-digit percentages of total supply voted. The minority that held to 'code is law' — that the hack was valid execution and the chain should not be altered — refused to upgrade. Their chain, now called Ethereum Classic, continues. The fork is the single most consequential cultural event in Ethereum history. It established that the Ethereum community would, under sufficient duress and with majority consensus, deviate from pure-cypherpunk immutability in favor of pragmatic intervention. This is what makes Ethereum usable for institutional actors — there is, at least theoretically, a social backstop. It is also precisely what limits its appeal to Bitcoin maximalists and ETC purists. The fork didn't resolve the tension between 'unstoppable code' and 'accountable governance'; it instantiated it as a permanent schism. Tim May's specter — the promise that cryptographic protocol could be made proof against human reversal — took its first serious institutional hit here. Not from a government, not from a regulator, but from the community itself, acting collectively and with deliberation. The question of whether this was the right call has never been definitively answered, and ETC's continued existence is the permanent reminder that the question remains open. Facts • Fork block: 1,920,000, July 20 2016, 13:20:40 UTC • Carbon Vote result (May–July 2016): ~87% pro-fork, but ~4–6% of total supply participated • Ethereum Classic chain retained PoW, the 'code is law' principle, and the original DAO state • ETC has maintained a market cap typically 1–3% of ETH's • Subsequent Ethereum-side state rollbacks: zero — no event since has approached this threshold • Vitalik later characterized it as a justifiable 'social slashing' unlikely to be repeated Primary Documents • EF Blog: Hard Fork Completed (July 20 2016) — https://blog.ethereum.org/2016/07/20/hard-fork-completed • Etherscan: Block 1,920,000 — https://etherscan.io/block/1920000