Layer 1, Rollups and Sidechains: The Key Differences

The place the Checking Occurs

Execution means making use of a transaction to replace balances or run utility code. Publishing the underlying information lets others independently reconstruct the report. Finality issues when that report turns into settled below the community’s guidelines; it’s not the identical as a bridge withdrawal being prepared.

OP Mainnet is an optimistic rollup: claims about its balances are handled as legitimate except efficiently challenged throughout a dispute window. Its fault-proof system lets challengers contest incorrect claims on Ethereum. This depends on somebody detecting and contesting an invalid declare.

Linea is a validity-proof rollup, generally known as a ZK-rollup. It provides a cryptographic proof {that a} batch was processed appropriately, which a contract verifies reasonably than replaying each transaction on Ethereum. These rollups nonetheless publish the info wanted to reconstruct their report.

Polygon PoS illustrates the sidechain mannequin: its Bor software program executes transactions and its Heimdall validators agree on blocks. It sends checkpoint summaries to Ethereum, not rollup validity proofs for its execution.

One Switch, Three Completely different Paths

Think about Alice sends Bob 10 tokens already held on the chosen community, ignoring charges. These are different examples, not the identical cash shifting by three networks.

• On Ethereum, Ethereum nodes test the switch, and Ethereum’s consensus course of finalizes the block containing it.
• On a rollup, the rollup processes the switch first. Bob can see a neighborhood affirmation earlier than the related information and proof or dispute course of have accomplished on Ethereum.
• On Polygon PoS, Polygon’s validators test and finalize the switch regionally. A later Ethereum checkpoint serves the bridge; it doesn’t change Polygon’s personal transaction checks.

If Bob later desires a supported asset on Ethereum by the community’s personal bridge, that may be a separate course of. OP Mainnet’s Normal Bridge has a seven-day problem interval. That does not imply each OP Mainnet switch takes seven days to finalize. Withdrawal proposals, proofs and finalization even have their very own timing necessities.

Linea doesn’t want that optimistic problem window, however withdrawals are usually not due to this fact instantaneous: batch proof verification and Ethereum finalization should occur. Polygon withdrawals require the related checkpoint to be submitted and verified on Ethereum earlier than the exit can end.

These distinctions additionally assist decode deployment reviews. The Defiant’s protection of SharpLink’s treasury technique involving Linea issues use of a rollup. Its report on Optimum’s Ethereum block-delivery deployment issues communication throughout the base community, not a brand new rollup settlement layer.

Proofs Do Not Take away Each Dependency

A sequencer orders rollup transactions. Management of that position is completely different from the facility to improve the contracts imposing the foundations. OP Mainnet’s documentation describes a Basis-operated sequencer and joint Basis/Safety Council management of upgrades, which may happen with out an improve delay. Its Guardian also can intervene within the dispute system.

Linea’s danger disclosure likewise says its Safety Council can pause and instantly improve the rollup. Bridges add their very own software program and management dependencies. Neither a validity proof nor an Ethereum connection ensures that bridge or utility code is freed from bugs.