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Protocol Upgrades

Ethereum Classic, despite its history, is not against all types of Hard Fork. Far from it; Hard Forking allows the protocol to be upgraded, to fix bugs, and add features that further the goal of enabling developers to "Build Unstoppable Applications".

The types of Hard Fork that Ethereum Classic will never implement are those like The DAO Fork, which do not address a defect in or enhancement of the protocol itself, but instead override Code is Law by modifying Smart Contracts in the application layer.

Ethereum Classic strategically maintains maximal compatibility with upstream Ethereum's EVM, which means contracts deployed to ETH can also be deployed to ETC, and Ethereum Classic inherits many valuable innovations born through research on Ethereum.

ETC Fork History



Launched under the slogan "Build Unstoppable Applications", Frontier was a live, but barebones implementation of the Ethereum project. It followed the successful Olympic testing phase. It was intended for technical users, specifically developers. Blocks had a gas limit of 5,000. This ‘thawing’ period enabled miners to start their operations and for early adopters to install their clients without having to ‘rush’.

Ice Age


The frontier thawing fork lifted the 5,000 gas limit per block and set the default gas price to 51 gwei. This allowed for transactions – transactions require 21,000 gas.



The Homestead fork looked to the future. It included several protocol changes and a networking change that gave Ethereum the ability to do further network upgrades.

ECIP-1015 was Ethereum Classic's First independent protocol upgrade after the DAO Hard Fork, which involved long-term gas cost changes for IO-heavy operations to mitigate transaction spam attacks.

Die Hard


The Die Hard fork delayed the difficulty bomb, reprised the EXP opcode and implemented replay protection, setting ETC's Chain ID to 61.



ECIP 1017 makes Ethereum Classic more Bitcoin-like by introducing an upper bound on the maximum absolute number of ETC and a method of degraded emission over time.

Defuse Difficulty Bomb


The Difficulty Bomb is delayed, with no other changes.



Enabled the outstanding Ethereum Foundation Spurious Dragon and Byzantium network protocol upgrades on the Ethereum Classic network in a hard-fork code-named Atlantis to enable maximum compatibility across these networks.



Enabled the outstanding Ethereum Foundation Constantinople and Petersburg network protocol upgrades on the Ethereum Classic network in a hard-fork code-named Agharta to allow maximum compatibility across these networks.

Enabled the outstanding Ethereum Foundation Istanbul network protocol upgrades on the Ethereum Classic network in a hard-fork code-named Phoenix to enable maximum compatibility across these networks.



ECIP 1099 calibrated the epoch length used in DAG calculations, switching from ETHash to ETCHash, It increased the network's security by allowing GPUs with 4GB of memory to mine ETC.



Enabled the Ethereum Foundation Berlin network protocol upgrade features, reaching maximum compatibility with Ethereum.



Enabled the Ethereum Foundation London network protocol upgrade features, maintaining maximum compatibility with Ethereum.

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The content on this website is user-generated and solely for informational purposes. Do not interpret any content as an endorsement of any product or service. There's "no official anything" in Ethereum Classic. Always do your own research, and remember: don't trust, verify!