The Phoenix network upgrade has activated on Ethereum Classic mainnet at block 10,500,839, completing the adoption of Ethereum's Istanbul hard fork changes.
Full Istanbul Compatibility
Phoenix brings the remaining Istanbul EIPs to ETC:
EIP-2200: Structured Definitions for Net Gas Metering
Rebalances gas costs for SSTORE operations, enabling more efficient smart contract patterns.
EIP-1884: Repricing for Trie-Size-Dependent Opcodes
Adjusts gas costs for opcodes based on actual computational requirements.
EIP-152: Blake2b Precompile
Adds a precompile for the Blake2b hash function, enabling interoperability with Zcash and other Blake2b-using systems.
EIP-1108: Alt_bn128 Precompile Gas Reductions
Reduces gas costs for elliptic curve operations, making privacy-preserving applications more affordable.
Significance
With Phoenix, Ethereum Classic achieved complete EVM compatibility with Ethereum up to the Istanbul fork. This ensures that smart contracts and development tools work consistently across both networks.