What is Sui?

Sui is a Layer-1 blockchain with smart contract capabilities, similar to other well known blockchains such as Ethereum and Solana. Sui blocks are created  by a set of Delegated Proof-of-Stake authorities known as validators, which perform checks on transactions in the network, incorporate them into blocks and propose their blocks to all other validators. Sui’s consensus protocol, Mysticeti, then puts transactions into an order before executing and finalising them.

Whilst on the surface this may sound similar to the workings of traditional blockchains, Sui attempts to uniquely optimise for a high speed, and high volume of transactions. Optimisation techniques include eschewing the account based data model employed by many traditional blockchains. In Ethereum, for example, transactions are instructions that detail changes to account balances. Information about an ERC20 token is stored within the smart contract which created it, meaning that all transactions that involve that token must interact with the same smart contract. In this approach, strict total ordering of transactions is needed so as to ensure account balances are accurately adjusted across the network and avoid double spending.

Sui instead utilises an object centric data model. In this model, everything in the network (such as tokens or NFTs) is represented as an object with a clearly specified owner. This data structure enhances scalability because Sui is able to treat transactions differently depending on the type of object they involve. Transactions involving objects that are owned by a single user can be processed in parallel to each other. This is because the owner is already specified within the object itself, and changes to one object do not affect others. Transactions involving shared objects which do not have a specified owner and can be interacted with by multiple users require a stronger consensus process and thus take slightly longer to finalise. Separating transactions in this manner creates “a multi-lane” system to validate transactions.

Mysticeti is the consensus protocol designed specifically for Sui. The protocol’s main aim is to reduce the number of messages that need to be exchanged between validators to reach consensus and execute transactions in as short a time as possible. Currently, Mysticeti can process simple asset transfer transactions (examples of which we will give in section: Two Types of Transaction) in 390 milliseconds, boasting one of the fastest speeds amongst any blockchains currently. This is essential for the Sui platform to deliver scalable decentralised applications for mainstream adoption.