Bitcoin Settlement and Finality

Yona has multiple levels of finalization.

Finality Checkpoint 1: Trusted. Yona Rollup has reported tx as final in sub-second time.

Finality Checkpoint 2: Trusted / Soft Confirmation. A transaction has been successfully committed to EigenDA. At this point, a rollup is committed to a public witness for the potential ZK fraud proof.

Finality Checkpoint 3: Validators Nodes Commitment. Node operators confirm the validity of the transaction. Anyone can challenge them by providing a ZK fraud proof.

Finality Checkpoint 4: Challenge period is over, no one challenged Node operators.

Finality Checkpoint 5: Bitcoin-Equivalent Finality. The transaction is stored as part of a DA batch commitment to Bitcoin Layer 1. This would sync it with Bitcoin chain progression and mark transactions as irreversibly final as soon as enough bitcoin blocks are mined.

As a result, Bitcoin acts as a settlement Layer in a sense that establishes a view of the state of a Yona rollup on Bitcoin. Settlement view is read-only and allows parties external to the Yona to make decisions based on the state of Yona on Bitcoin.

Once a transaction is published and finalized on the Data Availability layer and the state is committed to Bitcoin, the transaction is also finalized on Yona. Except for breaking the underlying Data Availability layer and Bitcoin consensus, it can no longer be modified or removed.