The storage-based consensus paradigm (Abbreviated as SCP. Former name: storage-based computation paradigm) is the next-generation paradigm for blockchain application development proposed by everFinance. The SCP is a development practice that anyone can use to build decentralized applications. A typical application is everpay.io, and other applications such as koii.network, kyve.network are also essentially an implementation of the SCP. Although the idea of SCP originated from SmartWeave, SmartWeave can also be considered as an implementation of SCP.

What is a SCP？

In Ethereum’s model, computations are executed by all the full nodes, which then generates and stores the global state for query. Different from it, the SCP manages to separate computation from storage. To be more specific, the blockchain is merely used for data storage, while the off-chain clients/servers are responsible for executing all the computations and storing all the states generated.

The SCP uses off-chain smart contracts, which can be written in any programming language, with all the inputs coming from a storage-based blockchain. In this paradigm, the blockchain is very much like a hard drive and the off-chain smart contracts can be run on any device with computing capabilities. Using a blockchain as a hard drive ensures the immutability and traceability of the stored data, which is thus guaranteed to be trusted. As a result, off-chain smart contracts can ensure the ultimate consistency of state by performing computations on trustable data. 

The applications built on top of the SCP feature both the transparency and trustworthiness of blockchains as well as the high performance and availability of traditional internet applications. The SCP has the following advantages:

1. Composability: Business operations between traditional financial services requires account checking, which is complex and error-prone. Using a SCP can include all the financial transaction records in the blockchain, thereby converting the traditional financial services into blockchain applications. This facilitates not only automated account checking, but also rapid coordination and efficient combination of applications.
2. Low Development Barriers: Smart contracts are required to be written in Solidity using an EVM, while off-chain computation programs can be written in any programming language. That Makes it so developers can convert traditional applications into blockchain applications.
3. No Performance Limitation: Off-chain computation delivers superior performances similar to traditional applications because the off-chain servers can process massive transactions. In this way, the TPS merely depends on the machine performance of servers and the technical architecture of applications.
4. Low Consensus Cost: It merely costs 1 dollar to process a million transactions.

Improving SmartWeave in practice

The SCP is designed by the inspirations of Arweave’s smart contract SmartWeave and Ethereum’s L2 scaling solution Rollup, which improves their availability.

SmartWeave is a smart contracting platform built on top of the Arweave network. It allows users and developers to build programs whose execution is trustable and decentralized. One of the unique features of SmartWeave is the process of lazy evaluation, which removes the burden of processing smart contracts from the nodes and moves it to the users. This means that, instead of running every piece of code on every machine in the network, contract states are computed locally on the machines that request them.

SmartWeave is a decentralized contract platform that is open to all. The off-chain computation enabled by SmartWeave delivers higher scalability at the expense of introducing a new problem. The problem lies in that SmartWeave is prone to DDoS attacks, which means a large amount of invalid data is transmitted to all the computing nodes via Arweave, leading to latency in consensus and unavailability. When DDoS attackers maliciously send massive false transactions to the blockchain, node clients have to download them before verifying, therefore taking up a large part of bandwidth. In this case, valid transactions are submerged in the flood of false transactions, lowering the accuracy rate of data. To some extent, DDoS attacks may even lead to latency in client state computation.

To prevent DDoS attacks and ensure the availability of applications, everFinance has introduced a coordinator to compute and verify all the data of applications for the first time, and then includes batches of data into the chain. The coordinator acts like a rollup built on top of Ethereum by packaging transactions in batches, then including them into the chain. All the data packaged can be verified, SmartWeave’s “lazy evaluation” ensures verifiability, and Rollups guarantee the data accuracy which helps avoid DDoS attacks.

Reference

• SmartWeave: Arweave smart contracts
• A Storage-based Computation Paradigm Enabled by Arweave
• A Speech on IPFSNEWS’s Blockchain Forum: A Storage Application Paradigm
• AMA recap with Chris by SnapFingers about Arweave, storage and more
• Evolution of the Blockchain Application Model along with Changing Consensus