Sui Lutris protocol: Combining DAG consensus and non-consensus methods to achieve high performance in Blockchain.

Blockchain technology has made significant progress since the birth of Bitcoin. With the emergence of new application scenarios such as gaming and NFTs, the industry is continuously exploring ways to improve technical efficiency, especially in handling high load and achieving real-time responses. L1 Blockchains face two major challenges: first, achieving high throughput while maintaining low latency, and second, ensuring the long-term stability of the consensus protocol. In addressing these challenges, decentralization should also be maintained through the dynamic participation and reconfiguration of validating Nodes.

One way to increase throughput is to use a DAG-based consensus protocol. Such protocols allow the Blockchain to handle a large number of transactions simultaneously, making them very suitable for application scenarios like games and NFTs. However, DAG-based protocols often lead to several seconds of latency, which is a high time cost for regular transfers or gaming operations.

On the other hand, consensus-free protocols demonstrate great potential in reducing latency and improving scalability. These protocols eliminate the need for consensus, allowing for the rapid processing of transactions without the need for global ordering of independent transactions that are processed in parallel. However, they are limited to a class of constrained simple blockchain operations, restricting the achievable smart contract functionality, and making it difficult to support dynamic reconfiguration of the validator set.

Despite the potential of these methods, none have been applied to production-level blockchains at this time. They mainly remain at the stage of academic conference publications and have not been widely adopted by the blockchain community. Sui Lutris is a protocol that supports the Sui network, combining DAG-based consensus and non-consensus methods to achieve the best of both worlds: sub-second latency and sustained throughput of thousands of transactions per second. Sui not only accomplishes these two tasks but also maintains the ability to express complex contracts on shared objects, generate checkpoints, and reconfigure the validator set across periods.

Sui Lutris adopts a unique approach by combining the two methods mentioned above. To ensure the security of single owner asset operations, the system employs a consistent broadcast protocol among validators, achieving latency below consensus. Sui Lutris relies solely on consensus to handle complex smart contracts running on shared objects. Additionally, Sui Lutris supports network maintenance operations such as defining checkpoints and reconfiguring validators. This innovative strategy provides a solution that balances high performance and security when processing transactions in a replicated Byzantine environment.

The transaction lifecycle of Sui Lutris includes the following steps: users create and sign the transaction, the transaction is sent to the verifying nodes, the verifying nodes perform checks and sign, the client collects responses from the verifying nodes to form a transaction certificate, and the certificate is sent back to the verifying nodes for confirmation. For exclusive object transactions, they can be processed immediately; other transactions are processed through a DAG-based Consensus protocol. The consensus outputs the total order of certificates, the verifying nodes execute shared object transactions, and the client collects responses to form effect certificates. Finally, a checkpoint is formed for each consensus submission to drive the reconfiguration protocol.

In addition to the main trading process, Sui Lutris also offers multiple features that support production-grade blockchain: implementing checkpoint protocols to generate a causal history of transactions; supporting reconfiguration at the end of each epoch; securely "unlocking" erroneously locked assets at the end of the epoch, minimizing damage caused by vulnerabilities.

Sui Lutris supports the Sui network, which is a blockchain designed specifically for managing large amounts of value. The complete technical report provides more details about the security and active protocol operations, as well as the security proofs concerning Byzantine participants with partial synchrony in the standard distributed system model.