Ethereum Deploys Latest Shadow Fork En Route to the Merge

Ethereum successfully completed one of the last tests required prior to the Merge—the blockchain’s much-anticipated and oft-delayed transition to proof of stake. 

The blockchain's ninth shadow fork went live 15 hours ahead of schedule this morning. Shadow forks, like today’s, practice making one or two particular changes that will take place during the Merge. Shadow forks are different from full testnet hard forks, like last week’s Sepolia testnet, which move the entire Ethereum mainnet over to a test environment network. 

Today’s shadow fork focused on testing Ethereum’s so-called MEV boost feature. MEV, or “maximal extractable value,” refers to the process by which the individuals who create new ETH can further profit by manipulating their control over the network and prioritizing certain users’ transactions.

ETH is currently created by “mining” for it with specialized hardware, but after the Merge, it will be earned by “validating,” or pledging large quantities of pre-existing ETH.

“With the change to proof of stake, validators will now be the ones executing MEV, so searchers (the people who find MEV) will need to get their bundles to validators now (rather than miners),” Ethereum core developer Micah Zoltu told Decrypt. “MEV Boost is basically that.”

The MEV boost feature will allow validators to offer space within blocks they create to other validators— a mechanism meant to encourage competition between validators, increase validating profits across the board, and dilute the risk of validators accumulating too much leverage over the order or cadence of user transactions. 

While the proof-of-stake method of creating new ETH, according to the Ethereum Foundation's estimates, will be 99% more environmentally-friendly than the current, energy-intensive proof-of-work model, it will also mean lower profits to the individuals involved. The Merge’s transition to proof of stake is likely to strand thousands of Ethereum miners, who will likely be unable to match the profit model of Ethereum mining post-Merge, and will be left holding the bag of incredibly costly mining hardware. 

Ethereum co-founder Vitalik Buterin has previously stated that the Merge, along with solving Ethereum’s sustainability issues, will also mitigate the risk of malicious miners who accept bribes to manipulate the order of on-chain transactions. Today’s successful shadow fork—which has yet seen no significant glitches—brings Ethereum one step closer to that reality.

Ethereum core developer Marius van der Wijden called today’s test “another step in the right direction.”

“We don’t learn that much new anymore with these shadow forks,” van der Wijden told Decrypt, “but they increase our confidence in the software.”

Only one major test, on the Goerli testnet, remains to be completed before the Merge is ready to take place. That test is expected to occur next month.