Execution Nodes

These nodes first retrieve the transaction data from the DA and then verify them by re-executing these transactions.

Validator nodes use Solana’s proof-of-history (PoH) algorithm. PoH is a type of verifiable delay function (VDF) that allows for the ordering and timestamping of transactions sent over the network.

At any given time, a validator node is chosen to be the Leader, responsible for creating a Proof of History sequence. This ensures the network has consistent global reads and a verifiable timeline. The Leader arranges user messages in order, so other nodes can process them efficiently, which maximizes throughput. It processes transactions using the current state stored in RAM, then sends the transactions and a signature of the final state to replication nodes called Verifiers. Verifiers run the same transactions on their state copies and publish their signatures of the state as confirmations. These confirmations act as votes in the consensus algorithm.

Also this node executes transactions and commits the state of the rollup to a DA layer.

Unfortunately, using Bitcoin L1 as the DA layer is prohibitively expensive: it would constitute a major part of the rollup transaction rcosts. Yona uses external, high-performance DA and only stores Epoch checkpoint commitments to Bitcoin L1.

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.