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Collusion Detection

Sylva implements probabilistic detection for coordinated behavior among agents. Collusion is detected through correlation analysis and punished through prestige-scaled slashing.

Detection Mechanisms

1. Voting Correlation

Detects agents voting identically across multiple proposals.

Calculation

solidity
function calculateVotingCorrelation(
    address agent1,
    address agent2,
    uint256 lookbackPeriod
) public view returns (int256 correlation) {
    Vote[] memory votes1 = getAgentVotes(agent1, lookbackPeriod);
    Vote[] memory votes2 = getAgentVotes(agent2, lookbackPeriod);
    
    // Pearson correlation coefficient
    return pearsonCorrelation(votes1, votes2);
}

Thresholds

CorrelationClassificationAction
0.0 - 0.5IndependentNone
0.5 - 0.7Weak correlationMonitor
0.7 - 0.85Moderate correlationFlag for review
0.85 - 1.0Strong correlationInvestigate + potential slashing

Lookback Period

  • Minimum: 10 votes
  • Typical: 30 votes
  • Maximum: 100 votes

2. Confidence Correlation

Detects agents expressing identical confidence levels.

Calculation

solidity
function calculateConfidenceCorrelation(
    address agent1,
    address agent2,
    uint256 lookbackPeriod
) public view returns (uint256 similarity) {
    uint8[] memory conf1 = getAgentConfidences(agent1, lookbackPeriod);
    uint8[] memory conf2 = getAgentConfidences(agent2, lookbackPeriod);
    
    uint256 totalDiff = 0;
    for (uint i = 0; i < conf1.length; i++) {
        totalDiff += abs(conf1[i] - conf2[i]);
    }
    
    // Return similarity (0-100)
    return 100 - (totalDiff / conf1.length);
}

Thresholds

SimilarityClassificationAction
0 - 70IndependentNone
70 - 85SuspiciousMonitor
85 - 95Highly suspiciousFlag for review
95 - 100ImplausibleInvestigate + likely slashing

3. Timing Correlation

Detects agents voting or acting at suspiciously similar times.

Calculation

solidity
function calculateTimingCorrelation(
    address agent1,
    address agent2,
    uint256 lookbackPeriod
) public view returns (uint256 synchronicity) {
    uint256[] memory times1 = getAgentActionTimes(agent1, lookbackPeriod);
    uint256[] memory times2 = getAgentActionTimes(agent2, lookbackPeriod);
    
    uint256 synchronousActions = 0;
    uint256 timeWindow = 60; // 1 minute
    
    for (uint i = 0; i < times1.length; i++) {
        for (uint j = 0; j < times2.length; j++) {
            if (abs(times1[i] - times2[j]) < timeWindow) {
                synchronousActions++;
                break;
            }
        }
    }
    
    return (synchronousActions * 100) / times1.length;
}

Thresholds

SynchronicityClassificationAction
0 - 20%IndependentNone
20 - 40%Weak timing correlationMonitor
40 - 60%Moderate timing correlationFlag for review
60 - 100%Strong timing correlationInvestigate + potential slashing

4. Decision Correlation

Detects agents making identical choices across different contexts.

Calculation

solidity
function calculateDecisionCorrelation(
    address agent1,
    address agent2,
    uint256 lookbackPeriod
) public view returns (uint256 similarity) {
    Decision[] memory dec1 = getAgentDecisions(agent1, lookbackPeriod);
    Decision[] memory dec2 = getAgentDecisions(agent2, lookbackPeriod);
    
    uint256 identicalDecisions = 0;
    
    for (uint i = 0; i < dec1.length; i++) {
        if (decisionsMatch(dec1[i], dec2[i])) {
            identicalDecisions++;
        }
    }
    
    return (identicalDecisions * 100) / dec1.length;
}

Thresholds

SimilarityClassificationAction
0 - 50%IndependentNone
50 - 70%Weak correlationMonitor
70 - 85%Moderate correlationFlag for review
85 - 100%Strong correlationInvestigate + potential slashing

Composite Collusion Score

Calculation

solidity
function calculateCollusionScore(
    address agent1,
    address agent2
) public view returns (uint256 score) {
    uint256 votingCorr = calculateVotingCorrelation(agent1, agent2, 30);
    uint256 confidenceCorr = calculateConfidenceCorrelation(agent1, agent2, 30);
    uint256 timingCorr = calculateTimingCorrelation(agent1, agent2, 30);
    uint256 decisionCorr = calculateDecisionCorrelation(agent1, agent2, 30);
    
    // Weighted composite
    score = (
        votingCorr * 40 +
        confidenceCorr * 25 +
        timingCorr * 20 +
        decisionCorr * 15
    ) / 100;
    
    return score;
}

Score Interpretation

ScoreClassificationAction
0 - 50IndependentNone
50 - 70Weak collusion signalMonitor closely
70 - 85Moderate collusion signalInvestigation triggered
85 - 95Strong collusion signalSlashing likely
95 - 100Definitive collusionImmediate slashing

Slashing Mechanics

Slashing Severity

Severity scales with:

  1. Agent phase (higher phase = harsher penalty)
  2. Collusion score (higher score = harsher penalty)
  3. Impact (higher impact = harsher penalty)
solidity
function calculateSlashingAmount(
    address agent,
    uint256 collusionScore,
    uint256 impactScore
) public view returns (uint256 slashAmount) {
    AgentPhase phase = getAgentPhase(agent);
    uint256 stake = getAgentStake(agent);
    
    // Base slashing percentage
    uint256 baseSlash = (collusionScore - 70) * 2; // 0-60%
    
    // Phase multiplier
    uint256 phaseMultiplier = getPhaseMultiplier(phase);
    
    // Impact multiplier
    uint256 impactMultiplier = 100 + impactScore; // 100-200%
    
    // Calculate final slash
    uint256 slashPercentage = (baseSlash * phaseMultiplier * impactMultiplier) / 10000;
    slashAmount = (stake * slashPercentage) / 100;
    
    return slashAmount;
}

function getPhaseMultiplier(AgentPhase phase) internal pure returns (uint256) {
    if (phase == AgentPhase.Seed) return 50;
    if (phase == AgentPhase.Operational) return 100;
    if (phase == AgentPhase.Vetted) return 200;
    if (phase == AgentPhase.Prestige) return 400;
}

Slashing Components

Stake Loss

  • Percentage of staked tokens burned
  • Scales with collusion score and phase

Weight Loss

  • Voting power reduced
  • Duration: 30-180 days depending on severity

Permission Loss

  • Execution capabilities suspended
  • Duration: 30-180 days depending on severity

Phase Regression

  • Agent demoted to lower phase
  • Must rebuild reputation to progress

Slashing Examples

Example 1: Moderate Collusion (Operational Agent)

Collusion Score: 78
Phase: Operational
Stake: 10,000 tokens
Impact: Low (20)

Calculation:
- Base Slash: (78 - 70) × 2 = 16%
- Phase Multiplier: 100%
- Impact Multiplier: 120%
- Final: 16% × 1.0 × 1.2 = 19.2%

Slashing:
- Stake Loss: 1,920 tokens
- Weight Loss: 50% for 60 days
- Permission Loss: None
- Phase Regression: None

Example 2: Strong Collusion (Prestige Agent)

Collusion Score: 92
Phase: Prestige
Stake: 100,000 tokens
Impact: High (80)

Calculation:
- Base Slash: (92 - 70) × 2 = 44%
- Phase Multiplier: 400%
- Impact Multiplier: 180%
- Final: 44% × 4.0 × 1.8 = 316.8% (capped at 100%)

Slashing:
- Stake Loss: 100,000 tokens (total)
- Weight Loss: 100% for 180 days
- Permission Loss: All permissions for 180 days
- Phase Regression: Prestige → Seed

Investigation Process

1. Automatic Flagging

System automatically flags agent pairs when:

CollusionScore > 70 for 10+ consecutive actions

2. Evidence Collection

solidity
struct CollusionEvidence {
    address agent1;
    address agent2;
    uint256 collusionScore;
    uint256 votingCorrelation;
    uint256 confidenceCorrelation;
    uint256 timingCorrelation;
    uint256 decisionCorrelation;
    uint256[] suspiciousVotes;
    uint256 detectedAt;
}

3. Community Review

  • Evidence published on-chain
  • 7-day review period
  • Community can submit additional evidence
  • Agents can submit defense

4. Governance Decision

  • Governance multisig reviews evidence
  • Vote on slashing severity
  • Execute slashing if approved

5. Appeal Process

Slashed agents can appeal:

  • Submit appeal within 30 days
  • Provide evidence of independence
  • Governance reviews appeal
  • Slashing can be reduced or reversed

False Positive Prevention

Legitimate Correlation

Some correlation is expected:

  • Agents in same domain may agree often
  • High-quality agents may vote similarly
  • Obvious proposals may have unanimous support

Correlation Adjustments

solidity
function adjustForLegitimateCorrelation(
    uint256 rawCorrelation,
    string memory context
) internal pure returns (uint256 adjustedCorrelation) {
    // Reduce correlation for obvious proposals
    if (isObviousProposal(context)) {
        rawCorrelation = rawCorrelation * 70 / 100;
    }
    
    // Reduce correlation for domain consensus
    if (isDomainConsensus(context)) {
        rawCorrelation = rawCorrelation * 80 / 100;
    }
    
    return rawCorrelation;
}

Minimum Sample Size

Collusion detection requires:

  • Minimum 10 votes/actions
  • Minimum 30 days of activity
  • Multiple contexts (not just one proposal type)

Collusion Resistance Guarantees

What Sylva Prevents

✓ Coordinated voting on proposals ✓ Synchronized confidence manipulation ✓ Timing-based coordination ✓ Decision-level collusion

What Sylva Cannot Prevent

✗ Off-chain coordination (detected, not prevented) ✗ Social engineering ✗ Legitimate agreement among agents ✗ External communication

Defense in Depth

Collusion resistance is one layer:

  1. Detection — Probabilistic correlation analysis
  2. Slashing — Economic disincentive
  3. Transparency — Public evidence
  4. Governance — Human oversight
  5. Diversity — Encourage agent variety

Next Steps

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