Consensus Mechanism

• Uses Proof of Staked Authority.
• Blocks are produced by a limited set of validators (21).
• Validators take turns to produce blocks in a PoA manner, similar to Ethereum’s Clique consensus design.
• Validator set are elected in and out based on a staking based governance.
• Block time is around 5 seconds or shorter.
• It requires limited time to confirm the finality of transactions, e.g. around 1-min level or shorter.
• There is no inflation of native token: BNB, the block reward is collected from transaction fees, and it will be paid in BNB.

Validator Quorum

• Anyone can compete to join as candidates to elect as a validator.
• The staking status decides the top 21 most staked nodes to be the next validator set, and such an election will repeat every 24 hours.
• BNB is the token used to stake for BSC.

Security and Finality

• Users are encouraged to wait until receiving blocks sealed by more than ⅔*N+1 different validators.
• Uses slashing logic to penalize Byzantine validators for double signing or inavailability.
• Slashing logic aims to expose the malicious validators in a very short time and make the “Clone Attack” very hard or extremely non-beneficial to execute.

Rewards

• All the BSC validators in the current validator set will be rewarded with transaction fees in BNB.
• The reward for validators is the fees collected from transactions in each block.
• Validators can decide how much to give back to the delegators who stake their BNB to them, in order to attract more staking.
• Every validator will take turns to produce the blocks in the same probability (if they stick to 100% liveness), thus, in the long run, all the stable validators may get a similar size of the reward.
• Some parts of the gas fee rewarded to relayers (who are they?) for Cross-Chain communication.

Relayers

• Relayers are responsible to submit Cross-Chain Communication Packages between the two blockchains. There are two different types of Relayers.
• Relayers for BC to BSC communication referred to as BSC Relayers.
• Relayer is a standalone process that can be run by anyone, and anywhere, except that Relayers must register themselves onto BSC and deposit a certain refundable amount of BNB.
• Relayers for BSC to BC communication are using the “Oracle” model, and so-called Oracle Relayers.
• Each of the validators must, and only the ones of the validator set, run Oracle Relayers. Each Oracle Relayer watches the blockchain state change. Once it catches Cross-Chain Communication Packages, it will submit to vote for the requests.