The Advances and Challenges of Blockchain Technology

Blockchain technology has made significant progress since the birth of Bitcoin. With the emergence of new applications such as games and NFTs, the industry is continuously exploring ways to improve technical efficiency, especially in handling high loads and providing real-time latency. L1 blockchains face two main challenges: first, achieving high throughput while maintaining low latency, and second, ensuring the long-term stability of consensus protocols. In addressing these issues, it is also necessary to maintain decentralization through the dynamic participation and reconfiguration of validation nodes.

One way to achieve high throughput is to use DAG-based consensus protocols. These protocols allow the blockchain to handle a large number of transactions simultaneously, making them very suitable for application scenarios such as gaming and NFTs. However, DAG-based protocols often result in a few seconds of latency, which can be a high time cost for regular transfers or game operations.

On the other hand, consensus-less protocols show great potential in reducing latency and scalability. These protocols eliminate the need for consensus, allowing for rapid 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, which restricts the smart contract capabilities that can be achieved, and reconfiguring a dynamically changing set of validators can be challenging.

Although these methods all have potential, they are currently mostly at the academic research stage and have not yet been widely applied in production-level Blockchains. Sui Lutris is an innovative protocol that combines DAG-based consensus and non-consensus methods, aiming to achieve the best of both worlds: sub-second latency and sustained throughput of thousands of transactions per second. At the same time, Sui Lutris maintains the ability to express complex contracts on shared objects, generate checkpoints, and reconfigure the validator set across periods.

The Innovative Approach of Sui Lutris

Sui Lutris adopts a unique approach that combines the two aforementioned technologies. For operations involving assets owned by a single owner (owned objects), the system employs a consistent broadcasting protocol among validators to achieve sub-consensus latency. For complex smart contracts running on shared objects, Sui Lutris relies solely on consensus for processing. Additionally, it supports network maintenance operations, such as defining checkpoints and reconfiguring validators. This novel strategy provides a balanced approach to handling transactions in a replicated Byzantine environment.

The Workflow of Sui Lutris

1. Users create and sign transactions to change the objects they own or mix objects.
2. Transactions are sent to each Sui Lutris validation node for verification and signing.
3. The client collects responses from most of the validation nodes to form a transaction certificate.
4. The certificate is sent back to all verification nodes for confirmation.
5. If the transaction only involves exclusive objects, it can be processed immediately (fast track).
6. All certificates are forwarded to the DAG-based consensus protocol.
7. The total order of consensus output certificates, validating nodes execute transactions that include shared objects.
8. The client collects the responses from the validating nodes and assembles the effect certificate as proof of transaction settlement.
9. Create checkpoints for each consensus submission to drive the reconfiguration protocol.

Additional Features of Sui Lutris

1. Checkpoint protocol: Implemented after achieving finality, generating the causal history of all transactions in the system.
2. Reconfiguration support: Conducted at the end of each period, allowing changes to the validator set and their voting power.
3. Asset Unlocking Mechanism: Safely "unlock" erroneously locked assets at the end of the period to minimize the impact of vulnerabilities.

Sui Lutris supports the Sui Blockchain and aims to manage a large amount of user value. The protocol provides security proofs in a standard distributed system model, demonstrating its reliability in a partially synchronous Byzantine environment.