Rollup - Chainlore

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Rollup


Type	Layer 2 scaling architecture
Main verification families	Optimistic proofs and validity proofs
Data publication on Ethereum	Calldata or blobs⁴
Operational roles	Sequencing, proposing state, challenging or proving
Risk framework	L2Beat stages and project risk assessments³

A rollup is a blockchain scaling system that executes transactions outside a base chain and publishes data and state commitments to that chain. Ethereum rollups use Ethereum to settle results while sharing the cost of publishing information across a batch of transactions. Optimistic and validity rollups differ in how those results are verified.¹²

VerificationReport an error

An optimistic rollup accepts proposed results subject to a challenge period. A challenger can dispute an invalid state transition using a fault or fraud proof. Security depends on the ability to detect and challenge bad results. Canonical withdrawals generally wait for the relevant dispute period to finish.¹

A validity rollup supplies a cryptographic proof that a proposed state transition follows its execution rules. Its settlement contract verifies that proof before accepting the transition. Systems often called zero-knowledge or ZK rollups use this approach, but proving correctness does not by itself make transaction data private. Their published data can remain public.²

Sequencing and data availabilityReport an error

A sequencer orders transactions and may give users an early confirmation. That response is distinct from final settlement on the base chain. Rollup designs differ in whether users can force inclusion through Ethereum and what happens when an operator stops responding.¹³

EIP-4844 introduced blob-carrying transactions as a data-publication mechanism. Blob data is separate from normal EVM execution data, and its fee market is distinct from ordinary execution gas. Blobs support cheaper data publication; they are not a substitute for the rollup's proof system or a promise of permanent archival storage.⁴²

Governance and risksReport an error

An administrator may retain power to change settlement contracts or proof systems. An emergency council may also bypass ordinary upgrade delays. Those powers affect whether users have time to exit an unwanted change, even where the underlying verification design is sound.³

L2Beat describes its stages as a measure of decentralisation and trust minimisation. It explicitly distinguishes that measure from security against bugs: a system controlled entirely by code can still have unsafe code. A project's stage should therefore be read alongside its individual risk analysis.³

TimelineReport an error

Date	Event
2022-02-25	EIP-4844 created⁴
2023-06	L2Beat introduces its stages framework³

ReferencesReport an error

^ ^a ^b ^c ethereum.org. Optimistic rollups. https://ethereum.org/en/developers/docs/scaling/optimistic-rollups/
^ ^a ^b ^c ethereum.org. Zero-knowledge rollups. https://ethereum.org/en/developers/docs/scaling/zk-rollups/
^ ^a ^b ^c ^d ^e L2Beat. Stages framework. https://l2beat.com/stages
^ ^a ^b ^c Buterin, V. et al. (2022). EIP-4844: Shard Blob Transactions. https://eips.ethereum.org/EIPS/eip-4844