Sui Lutris Report: Analysis of the Core Distributed System Protocol of the Sui Public Chain

Mysten Labs updated the Sui Lutris white paper on August 18, confirming the following key findings after months of testing:

1. Under the conditions of using PTBs and 5K TPS, Sui can process 140k to 150k operations per second, far exceeding the benchmark performance of the mainnet peak (approximately 700 TPS).

2. Even in the case where some validator nodes stop operating, Sui's final confirmation delay can still be maintained below 0.5 seconds.

The white paper provides a detailed description of the operation mechanism of Sui, along with security proofs and guidance on how external testers can reproduce relevant data in their own validation tests.

After the launch of the Sui mainnet, applications such as games and NFTs have already gone on-chain. The Sui Lutris technical report recently released by Mysten Labs introduces a distributed system that supports Sui, capable of achieving high throughput and long-term stability while maintaining low latency.

Since the emergence of Bitcoin, blockchain technology has made significant progress, with new application scenarios such as games and NFTs. The blockchain community continues to explore ways to improve efficiency, especially in handling high loads and providing real-time responses.

Currently, L1 blockchains face two major challenges: achieving high throughput while maintaining low latency, and ensuring the long-term stability of the consensus protocol. These challenges can be addressed through the dynamic participation and configuration of validating nodes.

An effective way to achieve high throughput is to use DAG-based consensus protocols, such as Narwhal/Bullshark used by Sui. These types of protocols allow for the simultaneous execution of a large number of transactions, making them suitable for applications such as games and NFTs. However, DAG-based protocols may lead to delays of several seconds, which can significantly affect common transactions or game operations.

On the other hand, non-consensus protocols excel in reducing latency and scalability, such as the FastPay prototype. These protocols can process transactions quickly without consensus, but are only suitable for a limited category of simple blockchain operations, which restricts the expressiveness of smart contracts and makes it difficult to reconfigure a dynamically changing set of validating nodes.

Although both protocols have potential, they have not yet been widely adopted in production-grade blockchains. Sui Lutris, as the protocol supporting the Sui network, combines the advantages of DAG-based consensus and non-consensus methods to achieve sub-second latency and sustained throughput of thousands of transactions per second. At the same time, Sui maintains the ability to express complex contracts on shared objects, generate checkpoints, and reconfigure the validator set across cycles.

fusion of consensus and no-consensus methods

Sui Lutris adopts a unique approach that combines the two aforementioned technologies. For asset operations owned by a single owner (unique objects), the system uses a consistent broadcast protocol among verification nodes to achieve latency below consensus. For complex smart contracts running on shared objects, Sui Lutris relies solely on consensus processing. Additionally, Sui Lutris supports network maintenance operations, such as defining checkpoints and reconfiguring verification nodes. This innovative strategy provides a solution that accommodates all parties when handling transactions in a replicated Byzantine environment.

The transaction lifecycle of Sui Lutris includes the following steps:

1. The user creates and signs a transaction to change the objects they own.

2. Transactions are sent to the Sui Lutris validation node via full nodes for validity and security checks.

3. The client collects the responses from most validation nodes to form a transaction certificate, at which point the transaction reaches a final confirmation status.

4. After the certificate is integrated, it is sent back to all validation nodes for verification. Transactions involving unique objects can be processed immediately (direct fast path), and all certificates are forwarded to the DAG-based consensus protocol.

5. Consensus output certificate number, verification nodes check and execute transactions containing shared objects.

6. The client collects responses from most of the validator nodes and assembles them into a valid certificate as proof of transaction settlement.

7. Submit a checkpoint for each consensus to drive the reconfiguration protocol.

Sui Lutris also offers other functionalities supporting product-level blockchains:

• Implement checkpoint protocol to generate historical records of all transactions.
• Support reconfiguration at the end of each cycle.
• Safely "unlock" assets that have been mistakenly locked at the end of the cycle.

Sui Lutris is the foundation of the Sui blockchain, and the complete technical report provides more details about the security and activity of the protocol operation, as well as the security proofs that are partially synchronized with Byzantine participants in the standard distributed system model.