# Emergency Response Procedures

## Overview

This document outlines emergency response procedures for the trustless bridge system, including incident response, pause procedures, and recovery steps.

## Emergency Contacts

- **Security Team**: security@d-bis.org
- **Operations Team**: ops@d-bis.org
- **On-Call Engineer**: [Contact Information]

## Incident Classification

### Critical (P0)
- Active exploit detected
- Funds at risk
- System compromise
- Immediate action required

### High (P1)
- Potential security vulnerability
- System instability
- Significant service degradation
- Action required within 1 hour

### Medium (P2)
- Minor security issue
- Performance degradation
- Action required within 24 hours

### Low (P3)
- Documentation issues
- Non-critical bugs
- Action required within 1 week

## Emergency Procedures

### 1. Pause Bridge Operations

**When to Use**: Active exploit, security incident, or critical bug detected

**Procedure**:

1. **Immediate Actions**:
   ```bash
   # Use multisig to pause contracts
   ./scripts/bridge/trustless/multisig/propose-pause.sh \
     <multisig_address> \
     <contract_address> \
     "Emergency pause - [reason]"
   ```

2. **Verify Pause**:
   ```bash
   cast call <contract_address> "paused()" --rpc-url $ETHEREUM_RPC
   # Should return: 0x0000000000000000000000000000000000000000000000000000000000000001
   ```

3. **Notify Stakeholders**:
   - Send alert to all users
   - Post status update
   - Notify security team
   - Document incident

4. **Investigate**:
   - Assess impact
   - Identify root cause
   - Develop fix
   - Test fix thoroughly

5. **Resume Operations** (after fix):
   ```bash
   # Unpause contracts
   cast send <contract_address> "unpause()" \
     --rpc-url $ETHEREUM_RPC \
     --private-key $PRIVATE_KEY
   ```

### 2. Emergency Withdrawal for LPs

**When to Use**: Liquidity pool at risk, emergency situation

**Procedure**:

1. **Assess Situation**:
   - Check liquidity pool status
   - Verify minimum ratio
   - Calculate available withdrawals

2. **Emergency Withdrawal** (if mechanism exists):
   ```bash
   # If emergency withdrawal function exists
   cast send <liquidity_pool_address> "emergencyWithdraw(uint256)" <amount> \
     --rpc-url $ETHEREUM_RPC \
     --private-key $PRIVATE_KEY
   ```

3. **Manual Recovery** (if needed):
   - Coordinate with LPs
   - Process withdrawals manually
   - Document all actions

### 3. Incident Response Playbook

**Step 1: Detection**
- Monitor alerts and logs
- Identify incident type
- Classify severity

**Step 2: Containment**
- Pause affected systems
- Isolate affected components
- Prevent further damage

**Step 3: Investigation**
- Gather evidence
- Analyze logs and transactions
- Identify root cause
- Assess impact

**Step 4: Remediation**
- Develop fix
- Test fix thoroughly
- Deploy fix
- Verify fix works

**Step 5: Recovery**
- Resume operations gradually
- Monitor closely
- Verify system health

**Step 6: Post-Incident**
- Document incident
- Conduct post-mortem
- Implement improvements
- Update procedures

## Common Scenarios

### Scenario 1: Fraudulent Claim Detected

1. **Detection**: Challenge submitted with valid fraud proof
2. **Automatic Action**: Bond slashed automatically
3. **Manual Action**: Monitor for patterns, investigate relayer
4. **Prevention**: Review relayer activity, consider blacklisting

### Scenario 2: Smart Contract Bug

1. **Detection**: Unexpected behavior, failed transactions
2. **Immediate Action**: Pause affected contracts
3. **Investigation**: Analyze bug, assess impact
4. **Fix**: Deploy fix or workaround
5. **Recovery**: Unpause after fix verified

### Scenario 3: Liquidity Crisis

1. **Detection**: Liquidity pool below minimum ratio
2. **Immediate Action**: Block withdrawals, alert LPs
3. **Recovery**: Encourage LP deposits, adjust parameters if needed
4. **Prevention**: Monitor liquidity ratios, set alerts

### Scenario 4: RPC Outage

1. **Detection**: RPC health checks failing
2. **Immediate Action**: Switch to backup RPC
3. **Recovery**: Restore primary RPC, verify connectivity
4. **Prevention**: Use multiple RPC providers, monitor health

## Communication Plan

### Internal Communication

1. **Immediate**: Notify on-call engineer
2. **Within 15 minutes**: Notify security team
3. **Within 1 hour**: Notify management
4. **Ongoing**: Regular status updates

### External Communication

1. **Users**: Status page, social media, email
2. **Partners**: Direct communication
3. **Public**: Transparent updates (without revealing sensitive details)

## Recovery Procedures

### After Pause

1. **Verify Fix**: Ensure issue is resolved
2. **Test Thoroughly**: Test all functionality
3. **Gradual Rollout**: Resume with small limits
4. **Monitor Closely**: Watch for issues
5. **Full Resume**: Gradually increase limits

### After Incident

1. **Post-Mortem**: Document lessons learned
2. **Improvements**: Implement fixes and improvements
3. **Monitoring**: Enhance monitoring and alerts
4. **Training**: Update team training

## Prevention

### Regular Activities

- Security audits
- Code reviews
- Testing
- Monitoring
- Documentation updates

### Best Practices

- Defense in depth
- Principle of least privilege
- Regular backups
- Disaster recovery testing
- Incident response drills

## References

- Multisig Operations: `docs/bridge/trustless/MULTISIG_OPERATIONS.md`
- Security Documentation: `docs/bridge/trustless/SECURITY.md`
- Monitoring Setup: `docs/monitoring/MONITORING_SETUP.md`