In the Eclipse settlement process, verifiers (Eclipse full nodes) re-execute transactions to compute the state of the blockchain again. This state is then compared against the computed state posted on Celestia. If there’s a discrepancy between the two states, verifiers can raise a challenge during the challenge period.

This challenge uses zk fraud proofs created by RISC Zero's zkVM. At a high level, this zk fraud proof consists the following information:

• The commitment to the inputs for a transaction.
• The transaction that’s resulting in the discrepancy.
• The proof of when the verifier re-executes the transaction on Ethereum, the resulting state is different compared to the one posted on Celestia.

The Eclipse Executor sends this zk proof to the settlement contract on Ethereum, which then verifies the proof against the merkle root of data available of the state of the Eclipse blockchain on Celestia.

If the challenge is successful, i.e., the proof doesn’t match with the merkle root, the Eclipse native bridge with Ethereum is rolled back to the last state that matches between data posted on Celestia and that on Ethereum.