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Istanbul is the codename given to the 8th major network upgrade (hard fork) for Ethereum.

EIP's Included

Istanbul includes 6 Ethereum Improvement Proposals (EIPs):

  • EIP-152: Adds the ability to verify the Equihash PoW within an ethereum contract. This will enable a relay and atomic-swap transactions between Zcash.
  • EIP-1108: Makes zk-SNARKs cheaper, allowing for cheaper scaling and privacy applications to be built. See Matter labs, Aztec, Rollup and Zether for examples.
  • EIP-1344: Adds a way for contracts to track the correct chain. To be used by contracts, especially those used by layer 2 (state channels, plasma), to follow the correct layer 1 chain, especially during a hard fork.
  • EIP-1884: Changes the cost of some EVM opcodes to prevent spamming attacks and to balance blocks better. The amount that must be paid for each operation in ethereum usually matches the computation required for that operation. This change increases some costs of some opcodes that are computationally intensive but currently cheap.
  • EIP-2028: Makes zk-SNARKs and zk-STARKs cheaper by reducing the cost of calling data within transactions. This will make layer 2 solutions able to increase throughput.
  • EIP-2200: Changes the calculation of cost of storage in the EVM and will enable contracts to introduce new functions including re-entry locks and same-contract multi-send.


  • 12/6/19 (Block 9,069,000) - Estimated Mainnet Upgrade Date