Consensus Mechanism

Paraloom uses distributed consensus to verify zkSNARK proofs across multiple validators.

Key Parameters

Components

Withdrawal Verification Coordinator

Manages consensus rounds for withdrawal verification.

pub struct WithdrawalVerificationCoordinator {
    pending_verifications: HashMap<String, WithdrawalConsensus>,
    validators: Arc<RwLock<HashMap<NodeId, ValidatorInfo>>>,
    reputation: Arc<ReputationTracker>,
    threshold: ConsensusThreshold,
}

Process:

1. Receive withdrawal request
2. Broadcast to all registered validators
3. Collect verification votes
4. Reach 7/10 consensus or timeout
5. Execute if approved

Leader Selection

Deterministic leader selection using stake + reputation weighting.

Formula:

weight = (stake × 0.7) + (reputation × 0.3)
leader = argmax(hash(seed || validator_id) × weight)

This ensures:

• Higher staked validators are more likely to lead
• Reputation influences selection (30% weight)
• Deterministic (all nodes agree on leader)
• Rotation on each round

Reputation Tracking

Automatic reputation updates based on verification behavior.

Bounds: 100 (minimum) to 10,000 (maximum)

Verification Flow

Byzantine Fault Tolerance

Threat Model

The system tolerates:

• 3/10 malicious validators - Can submit wrong votes
• Network partitions - Validators may be temporarily unreachable
• Crash failures - Validators may go offline

Safety Guarantees

Liveness

The system makes progress as long as:

• At least 7/10 validators are online
• Network allows message delivery
• Timeout hasn't expired

Multi-Validator Compute Verification

For compute jobs, the consensus model is slightly different:

2/3 Agreement Required:

• 3 validators execute same WASM job
• Results must match exactly
• 2/3 agreement for success

Why different threshold?

• Compute jobs are deterministic (WASM)
• Lower threshold for faster execution
• Still prevents single malicious validator

pub struct ComputeVerification {
    job_id: String,
    validators: Vec<NodeId>,
    results: HashMap<NodeId, Vec<u8>>,
    required_agreement: usize, // 2 of 3
}

Consensus Messages

Verification Request

pub struct VerificationRequest {
    request_id: String,
    proof: Vec<u8>,
    public_inputs: PublicInputs,
    timestamp: u64,
}

Verification Vote

pub struct VerificationVote {
    request_id: String,
    validator_id: NodeId,
    vote: Vote, // Approve, Reject, Abstain
    signature: Signature,
    timestamp: u64,
}

Consensus Result

pub struct ConsensusResult {
    request_id: String,
    outcome: Outcome, // Approved, Rejected, Timeout
    votes: Vec<VerificationVote>,
    final_timestamp: u64,
}

Configuration

Validator Configuration

[consensus]
threshold = 7
total_validators = 10
verification_timeout = 30  # seconds
reputation_bounds = [100, 10000]

[leader_selection]
stake_weight = 0.7
reputation_weight = 0.3

Network Configuration

[network]
gossipsub_heartbeat = 1  # second
peer_discovery = "mdns"
max_connections = 50