obront - Information passed to L1Block.sol is not delayed by 10 blocks

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obront

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Information passed to L1Block.sol is not delayed by 10 blocks

Summary

There is an inconsistency between the spec and the code regarding the timing of L1 block info being submitted to the L2 contract L1Block.sol.

Vulnerability Detail

In the spec, it states:

Currently the L1 information is delayed by ten block confirmations (~2.5 minutes) to minimize the impact of reorgs. This value may be reduced in the future.

However, in the node's derivation code, the L1 block information is included along with the deposits for each block as it's processed, with no delays.

This can further be verified by watching L1 as well as the L1Block contract, and observing that, for a given block, the information is posted to Optimism instantly.

• https://goerli.etherscan.io/
• https://goerli-optimism.etherscan.io/address/0x4200000000000000000000000000000000000015

Impact

Spec doesn't accurately reflect the reality of what the code is doing.

Code Snippet

https://community.optimism.io/docs/developers/bedrock/differences/#l1block

https://github.com/ethereum-optimism/optimism/blob/6c6d142d7bb95faa11066aab5d8aed7187abfe38/op-node/rollup/derive/attributes.go#L56-L68

Tool used

Manual Review

Recommendation

Remove this language from the spec or adjust the code to match.