Fraud Proof

What Is a Fraud Proof?

 A fraud proof is cryptographic evidence that a verifier submits to challenge the validity of a transaction.

How Do Fraud Proofs Work in Optimistic Rollups?

Fraud proofs play a crucial role in optimistic rollups to identify and handle invalid transactions. Whenever a transaction is approved, there is a specific dispute period where anyone can challenge the current state by presenting a valid fraud proof. If someone can prove a transaction is fraudulent during this window, it is nullified and the network readjusts to the previous state.

This system is in place to incentivize good behavior. If the network properly executes the rollups per the consensus rules, the concerned parties receive a financial reward. However, they face monetary penalties and risk forfeiting their fraud proof deposit if they approve an erroneous transaction. This dual approach of rewards and penalties ensures that the rollups remain cost-effective and fast, optimizing the performance of decentralized applications on a blockchain.

What Are the Limitations of Fraud Proofs?

Fraud proofs are not without their limitations. They require constant communication between multiple parties. This back-and-forth can lead to system disruptions and open the gates for dishonest behavior or other illicit actions.

Fraud Proofs vs. Validity Proofs