What a proof verifies
A zero-knowledge proof can let a verifier check that a computation followed specified rules, but the proof alone does not mean transaction data is stored so anyone can reconstruct it. Computational validity and data access are separate security questions.
Why state data matters
Ethereum documentation explains that rollup data availability supports independent verification and state reconstruction. Even if a validity proof verifies a state transition, users may be unable to check balances or submit new transactions if the operator withholds state data.
A hypothetical rollup outage
Suppose a hypothetical rollup operator submits proofs but does not distribute account state data. A verifier may check that the transition followed the rules, while users may still lack the information needed to reconstruct the next state. This is why data paths and escape mechanisms matter.
Proof types and data
An optimistic rollup may rely on a challenge period and fraud proofs; a zero-knowledge rollup uses validity proofs. For either, check where data is posted, how long it is available, and what pause authority belongs to the proof system or operator.
Withdrawal and reconstruction
In project documentation, locate transaction-data publication, batch-state queries, layer-one exits, forced inclusion, and reliance on external data providers. Review how long assets can be locked and who is responsible for recovery if data is lost.
Limits of verification
The label zero knowledge does not automatically guarantee privacy or trustless operations. Public inputs, circuit assumptions, prover roles, and data publication differ, so record what is verifiable and where operational trust remains.