Sui Lutris: A high-performance blockchain protocol combining DAG and no consensus technology.

Blockchain technology has made significant progress since the birth of Bitcoin. With the emergence of new application scenarios such as gaming and NFTs, the Blockchain Community continuously explores ways to improve technological efficiency, particularly in handling high loads and achieving real-time latency. 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, it is also necessary to maintain decentralization through the dynamic participation and reconfiguration of validating nodes.

One way to achieve high throughput is to use a DAG-based consensus protocol. Such protocols can handle a large number of transactions simultaneously, making them suitable for applications like games and NFTs. However, DAG-based protocols may result in a few seconds of latency, which can be a high time cost for regular transfers or game operations.

On the other hand, non-consensus protocols show great potential in reducing latency and scalability. These protocols eliminate the need for consensus, allowing for fast transaction processing without the need for a total 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 reconfiguring a dynamically changing validator set may pose challenges.

Although these methods have potential, they are not yet widely used in production-level blockchain. Sui Lutris is a protocol that supports Sui, 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 takes a unique approach by combining the two methods mentioned above. To ensure the security of asset operations owned by individual owners, the system employs a consistent broadcasting protocol among validators, achieving latency below consensus. Sui Lutris relies solely on consensus to handle complex smart contracts running on shared objects. It also supports network maintenance operations, such as defining checkpoints and reconfiguring validators. This novel strategy provides a win-win solution when processing transactions in a replicated Byzantine environment.

The transaction lifecycle of Sui Lutris is as follows: users create and sign transactions, which are sent to each validating Node. The validating Nodes perform validity and security checks, sign, and return to the client. The client collects responses from the majority of validating Nodes to form a transaction certificate, at which point the transaction is considered irreversible. The certificate is sent back to all validating Nodes for confirmation. If the transaction involves exclusive objects, it can be processed immediately without waiting for Consensus. All certificates are forwarded to a DAG-based Consensus protocol. The Consensus ultimately outputs the total order of certificates, and validating Nodes execute transactions that include shared objects. Clients can collect responses from validating Nodes and assemble them into an effect certificate as proof of transaction settlement.

In addition to the main trading process, Sui Lutris also offers multiple features that support production-grade Blockchain:

1. Implement checkpoint protocol to generate a causal history of all transactions in the system for complete auditing and synchronization.

2. Support for reconfiguration at the end of each period, the validator set and their voting power may change.

3. Safely "unlock" erroneously locked assets at the end of the epoch to minimize damage caused by the bug.

Sui Lutris provides support for the blockchain Sui, which manages a large amount of value. It offers a security proof of Byzantine participants with partial synchrony in the standard distributed system model, providing new ideas for building high-performance, secure, and reliable blockchain systems.