On-chain checksum of off-chain data

In order to solve the scalability problem of blockchain, off-chain data on-chain verification adopts a scaling expansion and consensus mech- anism similar to Layer-2 scheme to move some data and computation tasks to off-chain process- ing, while ensuring the security and integrity of on-chain data. This section will briefly introduce how to implement off-chain data on-chain verifica- tion by rollup scheme.

Rollup is a Layer-2 extension scheme, which aggregates the transaction data under the chain and then submits the aggregated data to the chain. Specifically the rollup scheme consists of the fol- lowing steps:

1. Off-chain data aggregation: In the off-chain environment, individual nodes handle the task of transferring and computing services for data sets. These nodes aggregate the transaction data to form a data structure called rollup.

2. On-chain data submission: The rollup data after aggregation is submitted to Layer- 1 networks, such as the Ethereum main chain. These submitted data include meta-data of aggregated transactions (meta- data), such as Merkle tree root node hash, etc.

3. On-chain data verification: Layer- 1 network nodes verify the submitted rollup data to ensure the correctness of the data under the chain. This process is mainly achieved by verifying the Merkle tree root node hash value.

The entire rollup off-chain data validation pro- cess can also be illustrated as follows:

Figure 7: Rollup off-chain data validation process

With the rollup scheme, a large amount of data and computation tasks can also be migrated from on-chain to off-chain processing, reducing the burden on the on-chain network and improving the throughput and scalability of the blockchain. At the same time, the rollup scheme ensures the security and integrity of off-chain data by submit- ting aggregated data to the Layer- 1 network and performing on-chain checksum.