Ethereum's four-minute finality proposal could cut crypto transfer costs

Ethereum researchers have proposed reducing transaction finality from about 16 minutes to roughly four, potentially lowering the cost of transfers between blockchains. Ben Edgington, the coordinator of Ethereum's fast-finality research, submitted the draft Wednesday with Francesco D'Amato, Roberto Saltini, Yann Vonlanthen and Mikhail Kalinin. The proposal initially seeks a four-fold improvement. The design remains incomplete and has no activation date.

Ethereum can include a transaction in a block before validators consider the transaction final. Finality marks the point when validators, the computers securing Ethereum, commit not to rewrite the transaction. Services moving funds away from Ethereum must decide when funds can safely be released on the destination network.

A transfer service could advance a customer's $10,000 transfer using funds already held on another network. The customer could receive funds within seconds, while the service would have $10,000 committed until the Ethereum transaction settles and repays the service. Ethereum Foundation research treats funds awaiting repayment as a cost for transfer services. Faster finality would allow services to reuse those funds sooner. A service advancing a steady $1 million per hour would have about $267,000 awaiting repayment under a 16-minute delay. However, a four-minute delay would reduce that amount to roughly $67,000.

Circle, the issuer of the dollar-pegged USDC stablecoin, already charges customers for faster transfers. Circle's fast transfer route from Ethereum currently charges 0.01%, equivalent to $1 per $10,000, excluding network and application charges. Circle's standard route has no Circle transfer fee. Circle limits the aggregate value of fast transfers awaiting final settlement. Each settlement releases capacity for additional fast transfers.

Ethereum validators currently cast one vote serving both block selection and the finalization of older blocks. Validators vote in rotation, and finality requires two complete voting rounds. Combining both functions in one vote limits finality speed to the pace of that rotation. The proposal would assign separate votes to the two functions, allowing finality to operate on a faster schedule that developers could progressively shorten. The researchers say separate votes would also simplify an eventual transition to quantum-resistant signatures. Ethereum would require that upgrade if quantum computers became capable of breaking the cryptography currently in use.

However, four-minute finality would remain slow compared with Solana's target. Solana activated the Alpenglow upgrade Wednesday, targeting finality of about 150 milliseconds. The Ethereum draft still had unresolved voting schedules, penalties and elements of the security analysis as of Thursday. Edgington wrote that "many aspects remain TBD". Edgington said the immediate objective was to obtain a proposal number, which would bring the idea into Ethereum's formal upgrade process.