A Quick Overview of Timeboost

Overview

Arbitrum has introduced Timeboost, an optional transaction ordering mechanism that augments the default First-Come, First-Served (FCFS) policy with a sealed-bid second-price auction for express-lane rights. This mechanism provides successful bidders with prioritized access to blockspace by bypassing an artificial delay applied to standard transactions.

Artificial Delay Mechanism

In Timeboost, all transactions submitted to Arbitrum’s sequencer are subject to a 200ms artificial delay before they are eligible for inclusion—except for those sent by the express-lane token holder. This delay functions as a "latency equalizer," ensuring that transaction ordering is no longer dictated solely by raw network latency.

Express Lane Auction Structure

• Round Duration Timeboost operates in 60-second rounds. Each round grants exclusive express-lane access to a single address, referred to as the round winner.

• Lane Control Rights The winning bidder may designate any address to act on their behalf for that round. This control can be delegated, sub-leased, or transferred. Gattaca leverages this capability by bidding for round access and redistributing express-lane privileges to searchers via an internal sub-auction.

• Transaction Wrapping When a searcher submits a transaction to Gattaca for express-lane inclusion, we automatically wrap the transaction in the express-lane format and sign it using the authorized token holder’s credentials. This signals to the Arbitrum sequencer that the transaction is exempt from the 200ms delay and should be prioritized accordingly.