Creating Stablecoin GDPR Compliance System: Data Privacy Protection

// GDPR compliance framework for stablecoin platforms
class StablecoinGDPRFramework {
  constructor() {
    this.principles = {
      lawfulness: new LawfulnessProcessor(),
      fairness: new FairnessAssessment(),
      transparency: new TransparencyManager(),
      purposeLimitation: new PurposeLimitationController(),
      dataMinimisation: new DataMinimisationEngine(),
      accuracy: new AccuracyMaintainer(),
      storageLimitation: new StorageLimitationManager(),
      integrityConfidentiality: new SecurityController(),
      accountability: new AccountabilityFramework()
    };
  }

  async assessGDPRCompliance(dataProcessingActivity) {
    const assessment = {
      lawful_basis: await this.principles.lawfulness.assess(dataProcessingActivity),
      legitimate_interests: await this.assessLegitimateInterests(dataProcessingActivity),
      data_minimisation: await this.principles.dataMinimisation.assess(dataProcessingActivity),
      purpose_limitation: await this.principles.purposeLimitation.assess(dataProcessingActivity),
      retention_compliance: await this.assessRetentionCompliance(dataProcessingActivity),
      security_measures: await this.assessSecurityMeasures(dataProcessingActivity),
      data_subject_rights: await this.assessDataSubjectRights(dataProcessingActivity)
    };

    return {
      overall_compliance: this.calculateComplianceScore(assessment),
      risk_areas: this.identifyRiskAreas(assessment),
      remediation_required: this.identifyRemediationActions(assessment),
      assessment_details: assessment
    };
  }

  async establishLawfulBasis(processingPurpose, dataType, userConsent) {
    const lawfulBases = {
      // Article 6(1)(a) - Consent
      consent: {
        applicable: userConsent && userConsent.freely_given && userConsent.specific,
        evidence: userConsent,
        withdrawable: true,
        requirements: ['clear_affirmative_action', 'granular_consent', 'easy_withdrawal']
      },
      
      // Article 6(1)(b) - Contract performance
      contract: {
        applicable: this.isNecessaryForContract(processingPurpose),
        justification: 'Processing necessary for stablecoin service delivery',
        evidence: 'Terms of service and user agreement'
      },
      
      // Article 6(1)(c) - Legal obligation
      legal_obligation: {
        applicable: this.isLegalObligationProcessing(processingPurpose),
        legal_reference: this.getLegalReference(processingPurpose),
        evidence: 'AML/KYC regulatory requirements'
      },
      
      // Article 6(1)(f) - Legitimate interests
      legitimate_interests: {
        applicable: await this.assessLegitimateInterests(processingPurpose, dataType),
        balancing_test: await this.performBalancingTest(processingPurpose, dataType),
        documentation: 'Legitimate interests assessment (LIA)'
      }
    };

    // Select most appropriate lawful basis
    const selectedBasis = this.selectOptimalLawfulBasis(lawfulBases, processingPurpose);
    
    return {
      lawful_basis: selectedBasis,
      documentation_required: this.getDocumentationRequirements(selectedBasis),
      ongoing_obligations: this.getOngoingObligations(selectedBasis)
    };
  }
}

// Privacy by Design architecture for stablecoin platforms
class PrivacyByDesignArchitecture {
  constructor() {
    this.dataFlowMapper = new DataFlowMapper();
    this.privacyEngineer = new PrivacyEngineeringTools();
    this.anonymizationEngine = new AnonymizationEngine();
  }

  async implementPrivacyByDesign(systemArchitecture) {
    const privacyArchitecture = {
      data_categorization: await this.categorizePersonalData(systemArchitecture),
      privacy_controls: await this.implementPrivacyControls(systemArchitecture),
      data_flows: await this.mapPrivacyDataFlows(systemArchitecture),
      anonymization: await this.implementAnonymization(systemArchitecture),
      encryption: await this.implementEncryption(systemArchitecture),
      access_controls: await this.implementAccessControls(systemArchitecture),
      audit_logging: await this.implementPrivacyAuditLogging(systemArchitecture)
    };

    return privacyArchitecture;
  }

  async categorizePersonalData(systemData) {
    const categories = {
      // Article 4(1) - Personal data
      personal_data: {
        identification_data: ['email', 'phone', 'name', 'address'],
        financial_data: ['wallet_addresses', 'transaction_history', 'balance_information'],
        technical_data: ['ip_addresses', 'device_fingerprints', 'session_data'],
        behavioral_data: ['trading_patterns', 'usage_analytics', 'preferences']
      },
      
      // Article 9 - Special categories
      special_categories: {
        biometric_data: ['facial_recognition', 'fingerprints', 'voice_patterns'],
        location_data: ['gps_coordinates', 'ip_geolocation'],
        health_data: [] // Not typically applicable for stablecoins
      },
      
      // Article 10 - Criminal conviction data
      criminal_data: {
        sanctions_screening: ['pep_status', 'watchlist_matches'],
        aml_data: ['suspicious_activity_reports', 'investigation_records']
      }
    };

    // Classify each data field
    const classified_data = {};
    for (const [category, subcategories] of Object.entries(categories)) {
      classified_data[category] = {};
      for (const [subcategory, fields] of Object.entries(subcategories)) {
        classified_data[category][subcategory] = await this.classifyDataFields(fields, systemData);
      }
    }

    return classified_data;
  }

  async implementDataMinimisation(dataCollectionPoints) {
    const minimisationRules = {
      kyc_data: {
        collect_only_required: ['name', 'date_of_birth', 'address', 'identity_document'],
        avoid_collection: ['social_security_number', 'detailed_financial_history'],
        retention_period: '5_years_post_relationship',
        deletion_triggers: ['account_closure', 'regulatory_retention_expiry']
      },
      
      transaction_data: {
        collect_only_required: ['amount', 'timestamp', 'counterparty_pseudonym'],
        avoid_collection: ['transaction_purpose', 'personal_notes'],
        anonymization_triggers: ['90_days_post_transaction'],
        blockchain_considerations: 'immutable_on_chain_data'
      },
      
      analytics_data: {
        collect_only_aggregated: ['user_counts', 'transaction_volumes'],
        avoid_individual_tracking: ['detailed_user_journeys', 'personal_preferences'],
        anonymization: 'immediate_upon_collection'
      }
    };

    return await this.applyMinimisationRules(dataCollectionPoints, minimisationRules);
  }

  async implementAnonymization(personalData) {
    const anonymizationTechniques = {
      k_anonymity: new KAnonymityProcessor(),
      l_diversity: new LDiversityProcessor(),
      t_closeness: new TClosenessProcessor(),
      differential_privacy: new DifferentialPrivacyEngine(),
      pseudonymization: new PseudonymizationEngine()
    };

    const anonymizationPlan = {
      transaction_data: {
        technique: 'pseudonymization',
        parameters: { key_rotation: '30_days', salt_generation: 'per_user' },
        reversibility: 'authorized_personnel_only'
      },
      
      analytics_data: {
        technique: 'differential_privacy',
        parameters: { epsilon: 0.1, delta: 1e_minus_5 },
        utility_preservation: 'statistical_analysis_accurate'
      },
      
      blockchain_data: {
        technique: 'address_anonymization',
        parameters: { new_address_per_transaction: true },
        linkability_protection: 'mixing_service_integration'
      }
    };

    return await this.executeAnonymizationPlan(personalData, anonymizationPlan, anonymizationTechniques);
  }
}

// Comprehensive Data Subject Rights implementation
class DataSubjectRightsManager {
  constructor() {
    this.rightsProcessors = {
      access: new RightOfAccessProcessor(),
      rectification: new RightOfRectificationProcessor(),
      erasure: new RightOfErasureProcessor(),
      restriction: new RightOfRestrictionProcessor(),
      portability: new RightOfPortabilityProcessor(),
      objection: new RightOfObjectionProcessor(),
      automated_decision_making: new AutomatedDecisionMakingProcessor()
    };
    this.responseTimeManager = new ResponseTimeManager();
  }

  async processDataSubjectRequest(request) {
    const validation = await this.validateRequest(request);
    if (!validation.valid) {
      return this.generateRejectionResponse(validation.reasons);
    }

    const processor = this.rightsProcessors[request.right_type];
    const response = await processor.processRequest(request);

    // Track response time compliance
    await this.responseTimeManager.trackRequest(request.id, request.right_type);

    return response;
  }

  async processRightOfAccess(userId, requestScope) {
    const personalDataExport = {
      // Article 15 - Right of access
      user_profile: await this.exportUserProfile(userId),
      kyc_data: await this.exportKYCData(userId),
      transaction_history: await this.exportTransactionHistory(userId, requestScope),
      wallet_addresses: await this.exportWalletAddresses(userId),
      preferences: await this.exportUserPreferences(userId),
      consent_records: await this.exportConsentRecords(userId),
      
      // Processing information
      processing_purposes: await this.getProcessingPurposes(userId),
      lawful_basis: await this.getLawfulBasisForUser(userId),
      retention_periods: await this.getRetentionPeriods(userId),
      data_recipients: await this.getDataRecipients(userId),
      third_country_transfers: await this.getThirdCountryTransfers(userId),
      
      // Rights information
      available_rights: this.getAvailableRights(),
      complaint_procedures: this.getComplaintProcedures()
    };

    // Generate human-readable export
    const exportFormat = await this.generateReadableExport(personalDataExport);
    
    return {
      export_data: personalDataExport,
      readable_format: exportFormat,
      export_timestamp: new Date(),
      validity_period: '30_days',
      download_instructions: this.getDownloadInstructions()
    };
  }

  async processRightOfErasure(userId, erasureRequest) {
    // Article 17 - Right to erasure ("right to be forgotten")
    const erasureAssessment = await this.assessErasureEligibility(userId, erasureRequest);
    
    if (!erasureAssessment.eligible) {
      return {
        request_status: 'rejected',
        rejection_reasons: erasureAssessment.rejection_reasons,
        legal_basis_for_retention: erasureAssessment.legal_basis
      };
    }

    const erasurePlan = {
      immediate_deletion: await this.identifyImmediateDeletionData(userId),
      anonymization_required: await this.identifyAnonymizationData(userId),
      blockchain_considerations: await this.assessBlockchainDataErasure(userId),
      third_party_notifications: await this.identifyThirdPartyNotifications(userId)
    };

    // Execute erasure plan
    const erasureResults = await this.executeErasurePlan(userId, erasurePlan);
    
    return {
      request_status: 'completed',
      erasure_results: erasureResults,
      completion_timestamp: new Date(),
      certification: await this.generateErasureCertificate(userId, erasureResults)
    };
  }

  async assessBlockchainDataErasure(userId) {
    // Special handling for immutable blockchain data
    const blockchainData = await this.getBlockchainData(userId);
    
    return {
      immutable_data: {
        transaction_hashes: blockchainData.transaction_hashes,
        wallet_addresses: blockchainData.wallet_addresses,
        erasure_approach: 'key_deletion_rendering_data_inaccessible'
      },
      
      off_chain_data: {
        transaction_metadata: 'can_be_deleted',
        user_annotations: 'can_be_deleted',
        analytics_data: 'can_be_anonymized'
      },
      
      privacy_preserving_measures: {
        key_deletion: 'private_keys_controlling_addresses_deleted',
        address_rotation: 'future_transactions_use_new_addresses',
        mixing_services: 'historical_transaction_linkability_broken'
      }
    };
  }

  async processRightOfPortability(userId, portabilityRequest) {
    // Article 20 - Right to data portability
    const portableData = {
      structured_data: await this.exportStructuredData(userId),
      machine_readable_format: 'JSON',
      standardized_schema: await this.getPortabilitySchema(),
      
      // Only data processed based on consent or contract
      consent_based_data: await this.getConsentBasedData(userId),
      contract_based_data: await this.getContractBasedData(userId)
    };

    // Generate portable export
    const portableExport = await this.generatePortableExport(portableData);
    
    return {
      portable_data: portableExport,
      export_format: 'application/json',
      schema_version: '1.0',
      transfer_instructions: this.getTransferInstructions(),
      compatibility_notes: this.getCompatibilityNotes()
    };
  }
}

// Cross-border transfer compliance manager
class CrossBorderTransferManager {
  constructor() {
    this.adequacyDecisions = new AdequacyDecisionTracker();
    this.sccs = new StandardContractualClausesManager();
    this.bcrs = new BindingCorporateRulesManager();
    this.certifications = new CertificationManager();
  }

  async assessTransferLegality(transferDetails) {
    const assessment = {
      destination_country: transferDetails.destination_country,
      data_categories: transferDetails.data_categories,
      transfer_purpose: transferDetails.purpose,
      
      // Chapter V transfer mechanisms
      adequacy_decision: await this.checkAdequacyDecision(transferDetails.destination_country),
      standard_contractual_clauses: await this.assessSCCsApplicability(transferDetails),
      binding_corporate_rules: await this.assessBCRsApplicability(transferDetails),
      certification_mechanisms: await this.assessCertifications(transferDetails),
      
      // Article 49 derogations
      derogations: await this.assessDerogations(transferDetails),
      
      risk_assessment: await this.performTransferRiskAssessment(transferDetails)
    };

    return {
      transfer_legal: this.determineTransferLegality(assessment),
      recommended_mechanism: this.recommendTransferMechanism(assessment),
      additional_safeguards: this.recommendAdditionalSafeguards(assessment),
      assessment_details: assessment
    };
  }

  async implementStandardContractualClauses(transferAgreement) {
    const sccImplementation = {
      // Use EU Commission SCCs (2021)
      applicable_sccs: 'Commission_Implementing_Decision_2021_914',
      
      modules: {
        module_1: transferAgreement.controller_to_controller,
        module_2: transferAgreement.controller_to_processor,
        module_3: transferAgreement.processor_to_processor,
        module_4: transferAgreement.processor_to_controller
      },
      
      docking_clause: transferAgreement.multi_party_agreement,
      
      // Annex I - Transfer details
      transfer_details: {
        data_subjects: await this.describeDataSubjects(transferAgreement),
        data_categories: await this.describeDataCategories(transferAgreement),
        sensitive_data: await this.identifySensitiveData(transferAgreement),
        processing_purposes: await this.describeProcessingPurposes(transferAgreement),
        retention_periods: await this.specifyRetentionPeriods(transferAgreement)
      },
      
      // Annex II - Technical and organizational measures
      technical_measures: await this.specifyTechnicalMeasures(transferAgreement),
      organizational_measures: await this.specifyOrganizationalMeasures(transferAgreement)
    };

    return await this.generateSCCsAgreement(sccImplementation);
  }

  async performTransferImpactAssessment(proposedTransfer) {
    // Article 35 GDPR + Schrems II requirements
    const tia = {
      // Legal framework assessment
      third_country_laws: await this.assessThirdCountryLaws(proposedTransfer.destination),
      government_access: await this.assessGovernmentAccessRisks(proposedTransfer.destination),
      judicial_redress: await this.assessJudicialRedress(proposedTransfer.destination),
      
      // Technical assessment
      encryption_in_transit: await this.assessTransitEncryption(proposedTransfer),
      encryption_at_rest: await this.assessRestEncryption(proposedTransfer),
      access_controls: await this.assessAccessControls(proposedTransfer),
      monitoring_capabilities: await this.assessMonitoring(proposedTransfer),
      
      // Organizational assessment
      data_processor_obligations: await this.assessProcessorObligations(proposedTransfer),
      incident_response: await this.assessIncidentResponse(proposedTransfer),
      audit_capabilities: await this.assessAuditCapabilities(proposedTransfer),
      
      // Risk mitigation
      additional_safeguards: await this.identifyAdditionalSafeguards(proposedTransfer),
      residual_risks: await this.assessResidualRisks(proposedTransfer)
    };

    return {
      transfer_recommended: this.recommendTransfer(tia),
      risk_level: this.calculateRiskLevel(tia),
      mitigation_measures: this.recommendMitigationMeasures(tia),
      monitoring_requirements: this.specifyMonitoringRequirements(tia),
      assessment_details: tia
    };
  }
}

// GDPR Privacy Impact Assessment engine
class PrivacyImpactAssessmentEngine {
  constructor() {
    this.riskAssessment = new PrivacyRiskAssessment();
    this.stakeholderEngagement = new StakeholderEngagement();
    this.mitigationPlanGenerator = new MitigationPlanGenerator();
  }

  async conductPIA(processingActivity) {
    const pia = {
      // Systematic description of processing
      processing_description: await this.describeProcessing(processingActivity),
      
      // Necessity and proportionality assessment
      necessity_assessment: await this.assessNecessity(processingActivity),
      proportionality_assessment: await this.assessProportionality(processingActivity),
      
      // Risk assessment
      privacy_risks: await this.identifyPrivacyRisks(processingActivity),
      risk_severity: await this.assessRiskSeverity(processingActivity),
      likelihood_assessment: await this.assessRiskLikelihood(processingActivity),
      
      // Mitigation measures
      existing_measures: await this.identifyExistingMeasures(processingActivity),
      additional_measures: await this.recommendAdditionalMeasures(processingActivity),
      
      // Stakeholder consultation
      stakeholder_views: await this.gatherStakeholderViews(processingActivity),
      data_subject_consultation: await this.consultDataSubjects(processingActivity)
    };

    return {
      pia_conclusion: this.determinePIAConclusion(pia),
      regulatory_consultation_required: this.assessRegulatoryConsultation(pia),
      ongoing_monitoring: this.specifyOngoingMonitoring(pia),
      review_schedule: this.establishReviewSchedule(pia),
      pia_details: pia
    };
  }

  async identifyPrivacyRisks(processingActivity) {
    const risks = {
      // High-risk processing scenarios per Article 35(3)
      systematic_monitoring: {
        identified: await this.assessSystematicMonitoring(processingActivity),
        risk_level: 'high',
        impact: 'loss_of_control_over_personal_data',
        mitigation: 'anonymization_and_consent_management'
      },
      
      special_categories: {
        identified: await this.assessSpecialCategories(processingActivity),
        risk_level: 'high',
        impact: 'discrimination_or_identity_theft',
        mitigation: 'explicit_consent_and_additional_security'
      },
      
      large_scale_processing: {
        identified: await this.assessLargeScaleProcessing(processingActivity),
        risk_level: 'medium_to_high',
        impact: 'mass_privacy_violation',
        mitigation: 'data_minimization_and_purpose_limitation'
      },
      
      profiling: {
        identified: await this.assessProfiling(processingActivity),
        risk_level: 'high',
        impact: 'automated_decision_making_discrimination',
        mitigation: 'human_intervention_and_explanation_rights'
      },
      
      vulnerable_data_subjects: {
        identified: await this.assessVulnerableSubjects(processingActivity),
        risk_level: 'high',
        impact: 'exploitation_of_vulnerable_individuals',
        mitigation: 'enhanced_protections_and_safeguards'
      }
    };

    return risks;
  }

  async recommendAdditionalMeasures(processingActivity, identifiedRisks) {
    const measures = {
      technical_measures: {
        encryption: {
          recommended: true,
          specification: 'AES-256 for data at rest, TLS 1.3 for data in transit',
          implementation_timeline: '30_days'
        },
        
        pseudonymization: {
          recommended: identifiedRisks.re_identification_risk > 0.3,
          specification: 'Cryptographic pseudonymization with key separation',
          implementation_timeline: '60_days'
        },
        
        access_controls: {
          recommended: true,
          specification: 'Role-based access control with principle of least privilege',
          implementation_timeline: '45_days'
        },
        
        audit_logging: {
          recommended: true,
          specification: 'Comprehensive audit trail with integrity protection',
          implementation_timeline: '30_days'
        }
      },
      
      organizational_measures: {
        privacy_training: {
          recommended: true,
          specification: 'Regular GDPR training for all staff handling personal data',
          frequency: 'quarterly'
        },
        
        incident_response: {
          recommended: true,
          specification: 'Data breach response procedures with 72-hour notification',
          testing_frequency: 'bi_annually'
        },
        
        data_governance: {
          recommended: true,
          specification: 'Privacy governance framework with clear accountability',
          review_frequency: 'annually'
        }
      },
      
      legal_measures: {
        privacy_notices: {
          recommended: true,
          specification: 'Layered privacy notices with clear consent mechanisms',
          update_frequency: 'as_needed'
        },
        
        data_processing_agreements: {
          recommended: true,
          specification: 'Article 28 compliant processor agreements',
          review_frequency: 'annually'
        }
      }
    };

    return measures;
  }
}

// Automated GDPR compliance monitoring system
class GDPRComplianceMonitor {
  constructor() {
    this.complianceRules = new ComplianceRuleEngine();
    this.alertManager = new ComplianceAlertManager();
    this.auditLogger = new ComplianceAuditLogger();
  }

  async initializeMonitoring() {
    const monitoringRules = {
      // Data retention monitoring
      retention_compliance: {
        frequency: 'daily',
        rule: 'identify_data_exceeding_retention_periods',
        action: 'automated_deletion_or_anonymization'
      },
      
      // Consent monitoring
      consent_validity: {
        frequency: 'daily',
        rule: 'verify_consent_validity_and_freshness',
        action: 'flag_expired_or_withdrawn_consent'
      },
      
      // Data subject rights monitoring
      rights_request_compliance: {
        frequency: 'hourly',
        rule: 'monitor_response_time_sla',
        action: 'escalate_overdue_requests'
      },
      
      // Cross-border transfer monitoring
      transfer_compliance: {
        frequency: 'real_time',
        rule: 'verify_transfer_mechanism_validity',
        action: 'block_non_compliant_transfers'
      },
      
      // Data breach monitoring
      breach_detection: {
        frequency: 'real_time',
        rule: 'detect_unauthorized_access_or_disclosure',
        action: 'trigger_breach_response_procedure'
      }
    };

    await this.deployMonitoringRules(monitoringRules);
    return monitoringRules;
  }

  async generateComplianceReport(reportingPeriod) {
    const complianceMetrics = {
      data_subject_rights: {
        total_requests: await this.countRightsRequests(reportingPeriod),
        response_time_compliance: await this.calculateResponseTimeCompliance(reportingPeriod),
        successful_erasures: await this.countSuccessfulErasures(reportingPeriod),
        portability_requests: await this.countPortabilityRequests(reportingPeriod)
      },
      
      consent_management: {
        total_consent_captured: await this.countConsentCaptures(reportingPeriod),
        consent_withdrawal_rate: await this.calculateConsentWithdrawalRate(reportingPeriod),
        consent_refresh_compliance: await this.assessConsentFreshness(reportingPeriod)
      },
      
      data_protection: {
        encryption_coverage: await this.assessEncryptionCoverage(),
        access_control_compliance: await this.assessAccessControlCompliance(),
        audit_log_completeness: await this.assessAuditLogCompleteness(reportingPeriod)
      },
      
      privacy_incidents: {
        total_incidents: await this.countPrivacyIncidents(reportingPeriod),
        notification_compliance: await this.assessNotificationCompliance(reportingPeriod),
        resolution_time: await this.calculateIncidentResolutionTime(reportingPeriod)
      }
    };

    return {
      reporting_period: reportingPeriod,
      overall_compliance_score: this.calculateOverallComplianceScore(complianceMetrics),
      compliance_metrics: complianceMetrics,
      risk_areas: this.identifyComplianceRiskAreas(complianceMetrics),
      recommendations: this.generateComplianceRecommendations(complianceMetrics)
    };
  }
}