BSC Validator Overview

BNB Smart Chain(BSC) relies on a system of multiple validators with Proof of Staked Authority (PoSA) consensus that can support short block time and lower fees. The most bonded validators in staking will have the opportunity to produce blocks. The double-sign detection and other slashing logics ensure security, stability, and chain finality.

BSC conducts a daily election process post 00:00 UTC to select the top 45 active validators based on their staking rankings for block production. Among these, the 21 validators with the highest staked amounts are referred to as Cabinets, while the remaining 24 validators are known as Candidates. The remaining inactive validators must wait for the next round of elections to become active validators before they can participate in block production.

In the set of 45 active validators, each epoch selects 18 validators from the Cabinets and 3 validators from the Candidates, forming a group of 21 validators as the consensus validators set for the current epoch to produce blocks. If a validator is elected as the consensus validator but fails to participate in produce blocks, it will face slashing consequences.

Cabinets are more likely to be elected as consensus validators for block generation than Candidates, who have a slightly lower probability of being chosen for the same role. However, whether it’s Cabinets or Candidates, if they are not online when it’s their turn to produce a block, they will be slashed. This measure aims to encourage more validators to participate in the consensus, enhancing the decentralization and security of BSC.

What is Validator?

Validators on the BSC are nodes responsible for producing blocks and securing the network through the POSA consensus mechanism. They participate in packaging transactions, creating and validating blocks to secure the BSC network, earning BNB tokens as rewards in exchange.

Economics

Validator’s rewards come from transaction fees and commission fees from delegators.

Let us also assume that the reward for a block is 100 BNB and that a certain validator has 20% of self-bonded BNB and sets its commission rate to 20%. These tokens do not go directly to the proposer. Instead, they are shared among validators and delegators. These 100 BNB will be distributed according to each participant’s stake:

Commission: 80*20%= 16 BNB
Validator gets: 100\*20% + Commission = 36 BNB
All delegators get: 100\*80% - Commission = 64 BNB

The rewards for motivating validators to vote for Fast Finality also comes from transaction fees. The specific rules can refer to BEP126

If validators double sign, malicious vote or frequently offline, their staked BNB (not including BNB of users that delegated to them) can be slashed. The penalty depends on the severity of the violation.

You can learn to see the revenue history from BitQuery’s chart or a table of BscScan

Risks for Validators

If validators attempt to cheat the system or violate the specifications, they may incur a penalty known as slashing.

Double Sign Slash

Running your validator keys simultaneously on two or more machines will result in Double-Sign slashing. The penalty for double-sign slash:

1. 200 staked BNB will be slashed for the validator.
2. The double sign jail time is 30 days, preventing the malicious validator from participating in consensus until manual intervention is taken.

Note: Rewards for submitting double-sign evidence: 5BNB. Anyone can submit a slashing request with the evidence of double sign, which should contain the 2 block headers with the same height and parent block, sealed by the offending validator.

Malicious Fast Finality Vote Slash

Running your validators with the same consensus keys and bls voting keys concurrently on two or more machines will result in malicious vote slash. The penalty for malicious vote slash:

1. 200 staked BNB will be slashed for the validator.
2. The malicious vote jail time is 30 days, you can send an unjail transaction after the jail time to reactivate your validator.

Note: Rewards for submitting Malicious Vote evidence: 5BNB. Anyone can submit a slash request with the evidence of malicious vote on BSC, which should contain the 2 votes, signed by the offending validator.

Downtime Slash

If your validator misses over 50 blocks in 24 hours, the blocking reward won’t be given to you but will be shared among other validators. If your validator continues to miss more than 150 blocks within 24 hours, it will trigger the following penalty for being offline.

1. 10 staked BNB will be slashed for the validator.
2. The offline jail time is 2 days. This allows the validator to send an unjail transaction and resume as an active validator after 2 days.

Low Self-Delegation Slash

Validators must stake a minimum of 2000 BNB for self-delegation. If the self-delegated amount is less, the penalty is 2 days of jail time.