Validator Election
Last updated
Last updated
Validators are essential to the Core network, as they manage transaction validation and block production. Core’s Satoshi Plus consensus combines Delegated Proof of Work (DPoW), Delegated Proof of Stake (DPoS), and Non-Custodial BTC staking, creating a secure, decentralized validator election process that incorporates contributions from Bitcoin miners, CORE stakers, and BTC stakers. With the introduction of Dual Staking, BTC stakers who also simultaneously stake CORE gain access to higher BTC staking reward tiers, strengthening network security and incentivizing deeper engagement within the Core ecosystem.
Before the Fusion upgrade, a hardfork release of the Core blockchain, the hybrid score in Core incorporated contributions from Bitcoin miners (through hash power delegation), CORE token stakers, and BTC stakers. This scoring mechanism ensured that all three components contributed proportionally to validator selection. The formula used was:
Where:
rHp: Bitcoin hash power delegated to a validator.
tHp: Total hash power on Core.
rSp: Amount of CORE tokens staked to a validator.
tSp: Total CORE tokens staked on Core.
rBp: Amount of BTC tokens staked to a validator.
tBp: Total BTC tokens staked on Core.
m: Weight assigned to hash power (0 < m < 1).
n: Normalization factor determining the relative weight of CORE to BTC in staking calculations.
While this formula accounted for all three components, the proportional contributions of CORE staking, BTC staking, and hash power delegation, it also leads to the hybrid score being dynamic and variable over time, dependent on staking behaviour and network activity.
Even though the hybrid score is still influenced by the ratio of contributions from CORE staking, BTC staking, and hash power delegation, the Fusion Upgrade introduces variability in the weight of BTC staking and the weight of CORE staking stemming from the staking ratios of BTC and CORE for boosted yield tiers. The updated formula for hybrid score calculation is as follows:
Where, m + k + l = 1
rHp: Bitcoin hash power delegated to a validator.
tHp: Total hash power on Core.
rSp: Amount of CORE tokens staked to a validator.
tSp: Total CORE tokens staked on Core.
rBp: Amount of BTC tokens staked to a validator.
tBp: Total BTC tokens staked on Core.
m: Ratio assigned to hash power.
k: Ratio assigned to CORE staking.
l: Ratio assigned to BTC staking.
Stability and Predictability: Fixed ratios (m + k + l = 1) ensure a consistent and proportional distribution of contributions from hash power, CORE staking, and BTC staking, eliminating fluctuations caused by variable staking activity.
Governance Flexibility: The values of m, k, and l are configurable through governance, enabling the network to adapt to evolving dynamics while maintaining proportional fairness.
Simplified Calculations: Normalizing BTC staking contributions with a fixed l removes the need for additional normalization factors, reducing the complexity of hybrid score computations.
After the election, all validators are sorted roughly in order of their , and they take turns producing blocks in a round-robin manner before the process starts over again from the beginning. By initially limiting the number of validators to 21, which is now scaled up to 27, Satoshi Plus offers a higher transaction rate and increased scalability, but the number of validators is expected to increase over time as the network grows. What’s more, this mechanism provides additional security through improved efficiency and a tolerance for a large number of .
Slashing and jailing are the two basic mechanisms Core uses to disincentivize validator misbehaviour, and understanding how they work will go a long way toward making the incentive structure in Core more comprehensible.
First, “slashing” refers to cutting either the rewards a validator would have received in exchange for mining blocks or slashing the deposit of CORE tokens that a node makes to become a validator in the first place. The severity of the slashing punishment is scaled up in proportion to the validator’s misbehaviour. It is to be noted here that these penalties in the form of Slashing do not apply to the delegators’ staking principal (CORE or BTC).
Slashing penalties are generally incurred because a node fails to successfully produce a block during its designated turn in the round-robin block-mining procedure described above. If a validator node fails to mine 50 blocks in a round, the CORE rewards the validator has accrued so far are . Think of this as being equivalent to a misdemeanour. If a block fails to mine 150 blocks in a round, they surrender their share of the daily CORE rewards, they lose 10% of the deposit made to become a validator, and they are jailed for three days, which means they aren’t eligible to be elected to the validator set. Think of this as being equivalent to a .
Verifiers are responsible for reporting malicious behaviours on the network through slash suggestions. Slash suggestions can be submitted by anyone and are designed to punish malicious actors. The submission requires evidence of wrongdoing, but the rewards earned greatly exceed the costs if the allegations prove true.
There is a way for a validator to be permanently banned from the network by “double signing,” i.e., signing two different blocks at an equal block height. Whereas unavailability could plausibly result from a bad network connection, double signing is strong evidence of . Validators caught double signing surrender all rewards, 100% of their validator deposit, and are thereafter barred from participating in mining blocks.
As with slash suggestions, verifiers are charged with reporting double signing and must submit evidence of this activity. If their allegations are borne out, they are rewarded for keeping the network safe.
While producing blocks, the existing Core validators periodically check whether any current validator has been jailed. If so, they will update the validator set after an epoch (i.e., after 10 minutes). Jailing is designed to exclude misbehaving validators from consensus activities to enhance network security and keep TPS stable.