GDPR-Compliant PII Search System

Privacy-Preserving Search with Redis vs Database Performance Comparison

🎯 Project Overview

A production-ready GDPR-compliant PII search system offering two technically equivalent approaches for privacy-preserving search operations. Both approaches provide identical security guarantees and search results with different performance characteristics.

🔐 Core Features

✅ GDPR Compliant: Full encryption, pseudonymization, k-anonymity protection
✅ Zero PII Exposure: Search without decrypting sensitive data
✅ Functionally Identical: Redis and Database approaches return same results
✅ Enterprise Security: Military-grade encryption, audit trails, retention management
✅ Comprehensive Search: Equality, prefix, suffix, contains, complex queries
✅ Multi-Ethnic Data: Realistic test data with diverse names and patterns

🏗️ Two Equivalent Approaches

Feature	Redis Approach	Database Approach	Status
GDPR Compliance	✅ Full compliance	✅ Full compliance	IDENTICAL
Search Accuracy	✅ 100% correct	✅ 100% correct	IDENTICAL
Security	✅ HMAC + encryption	✅ HMAC + encryption	IDENTICAL
Performance	⚡ 2.67ms average	📊 5.50ms average	2x faster
Audit Trail	✅ Standard	🏆 Enhanced	DB advantage
Durability	✅ Memory + snapshots	🏆 ACID transactions	DB advantage

🚀 Super Quick Start

Step 1: Configuration Setup

Copy the environment template and configure for your setup:

# Copy environment template
cp .env.template .env

# Edit .env file with your database credentials and preferences
# Key configuration options:
#   DB_PASSWORD=your_postgres_password
#   NUMBER_OF_PEOPLE=5000  (adjust based on your testing needs)
#   CAUCASIAN_PERCENTAGE=30, ASIAN_PERCENTAGE=35, INDIAN_PERCENTAGE=35

Default Configuration (.env file):

Step 2: Service Setup & Testing

# Terminal 1: Start Vault server
vault server -dev -dev-root-token-id root -dev-tls

# Terminal 2: Start Redis server
redis-server

# Terminal 3: Install and run
npm install
npm run pipeline              # Generate data + build both indexes (DB & Redis)
npm run perf-test            # Compare performance (identical results guaranteed)

Expected Result: Both approaches return identical tokens with Redis ~2x faster

📋 Complete Documentation Suite

📚 Business Documentation

Executive Briefing - GDPR compliance and business benefits
GDPR Compliance Report - Detailed regulatory analysis
Technical Deep Dive - Implementation details with examples

🎯 Key Documents

Executive Summary: Business value, GDPR compliance, decision framework
Compliance Report: Article-by-article GDPR analysis, risk assessment
Technical Guide: HMAC key generation, search logic, concrete examples

⚡ Performance Comparison Results

Latest Test Results (September 2025)

📈 Performance Test Suite (6 scenarios):
┌─────────────────────────────────────────┐
│          SEARCH PERFORMANCE             │
├─────────────────────────────────────────┤
│  Redis Average:     2.67ms              │
│  Database Average:  5.50ms              │
│  Speed Difference:  2.06x               │
│  Result Accuracy:   100% identical      │
│  Compliance Status: Both fully compliant│
└─────────────────────────────────────────┘

✅ PERFECT: All approaches returned identical tokens
✅ VERIFIED: Complete functional equivalence

Performance Test Commands

npm run perf-test                    # Comprehensive 7-query test suite
npm run perf-test-single            # Single query performance test
npm run perf-test-complex           # Complex AND/OR query testing
npm run perf-test-validate          # Result validation and accuracy check

🔍 GDPR-Compliant Search Architecture

Privacy-Preserving Search Flow

┌─────────────────┐    ┌──────────────────┐    ┌─────────────────┐
│  Search Query   │───▶│  HMAC Transform  │───▶│  Index Lookup   │
│ "Find emails    │    │                  │    │                 │
│  containing     │    │ ┌──────────────┐ │    │ ┌─────────────┐ │
│  'gmail'"       │    │ │Query→3-grams │ │    │ │Redis/DB     │ │
└─────────────────┘    │ │HMAC each gram│ │    │ │Intersection │ │
                       │ └──────────────┘ │    │ └─────────────┘ │
                       │                  │    └─────────────────┘
                       │ ┌──────────────┐ │             │
                       │ │k-Anonymity   │ │◀────────────┘
                       │ │Filter (≥5)   │ │
                       │ └──────────────┘ │
                       └──────────────────┘
                                │
                       ┌────────▼─────────┐
                       │ Opaque Tokens    │
                       │ (No PII exposed) │
                       └──────────────────┘

Search Operations Supported

eq - Exact match: FIRST_NAME equals "John"
startsWith - Prefix search: EMAIL startsWith "john"
endsWith - Suffix search: LAST_NAME endsWith "smith"
contains - Substring search: ADDRESS contains "street"

Complex Query Support

# AND operations
FIRST_NAME equals "John" AND LAST_NAME startsWith "S"

# OR operations
EMAIL contains "gmail" OR EMAIL contains "yahoo"

# Field-specific searches
CITY startsWith "Mum" AND COUNTRY equals "India"

🏗️ System Architecture

Data Ingestion Pipeline

┌─────────────────┐    ┌──────────────────┐    ┌─────────────────┐
│  Raw PII Data   │───▶│ Vault Encryption │───▶│ Encrypted Store │
│                 │    │  (AES-256-GCM)   │    │                 │
│ • Multi-ethnic  │    │                  │    │ • pii_token_data│
│   names         │    │ ┌──────────────┐ │    │ • Opaque tokens │
│ • Realistic     │    │ │ HMAC Secrets │ │    │                 │
│   addresses     │    │ └──────────────┘ │    └─────────────────┘
│ • Email patterns│    └──────────────────┘             │
└─────────────────┘                                     │
                       ┌────────────────────────────────┘
                       ▼
        ┌─────────────────────────────────────────┐
        │         Dual Index Generation           │
        │                                         │
        │  ┌─────────────────┐ ┌─────────────────┐│
        │  │   Redis Index   │ │Database Index   ││
        │  │                 │ │                 ││
        │  │ • 181K+ keys    │ │• 181K+ keys     ││
        │  │ • Memory-based  │ │• ACID compliant ││
        │  │ • 2.67ms avg    │ │• 5.50ms avg     ││
        │  └─────────────────┘ └─────────────────┘│
        └─────────────────────────────────────────┘

Pipeline Commands

npm run pipeline              # Full pipeline: generate→encrypt→import→index both approaches
npm run build-index          # Build Redis search index
npm run build-db-index       # Build database search index
npm run generate-pii         # Generate diverse PII test data
npm run encrypt-csv          # Encrypt data with Vault
npm run import-csv           # Import to database + build Redis index

🔐 GDPR Compliance Features

Data Protection Principles Implementation

✅ Lawfulness: Explicit consent-based processing
✅ Purpose Limitation: Search-only data usage
✅ Data Minimization: Only necessary fields indexed
✅ Storage Limitation: Automated retention cleanup
✅ Integrity & Confidentiality: AES-256 encryption + HMAC protection
✅ Accountability: Comprehensive audit logging

Data Subject Rights Support

# All GDPR rights fully implemented:
✅ Right to be Informed      - Privacy notices and consent
✅ Right of Access          - Token-based record retrieval
✅ Right to Rectification   - Update encrypted records
✅ Right to Erasure         - Automated deletion workflows
✅ Right to Restrict        - Access controls and permissions
✅ Right to Data Portability - Export functionality
✅ Right to Object          - Opt-out mechanisms

Automated Compliance Features

Daily retention cleanup with compliance certificates
Tamper-evident audit trails for regulatory reviews
k-anonymity protection (suppresses results < 5 matches)
Comprehensive logging without PII exposure

📊 Technical Implementation Details

HMAC Key Generation Example

// For search query: FIRST_NAME contains "john"
Field: "FIRST_NAME" → "fn" (alias)
Value: "john" → normalized
Secret: process.env.REDIS_HMAC_SECRET

// Generate 3-grams: ["joh", "ohn"]
3-gram "joh": HMAC_SHA256(secret, "fn|joh") → "idx:fn:g3:Kx7mN9..."
3-gram "ohn": HMAC_SHA256(secret, "fn|ohn") → "idx:fn:g3:Lm8oP1..."

// Search: Intersect both keys → return matching tokens

Storage Comparison

-- Redis Storage
SADD "idx:fn:g3:Kx7mN9..." "TKN_ABC123_FIRST_NAME"
SADD "idx:fn:g3:Lm8oP1..." "TKN_ABC123_FIRST_NAME"

-- Database Storage
INSERT INTO pii_search_index (hmac_key, token_set, field_type)
VALUES ('idx:fn:g3:Kx7mN9...', 'TKN_ABC123_FIRST_NAME', 'FIRST_NAME');

Search Result Verification

Both approaches guarantee identical results:

Redis tokens:    [TKN_ABC123_FIRST_NAME, TKN_XYZ789_FIRST_NAME]
Database tokens: [TKN_ABC123_FIRST_NAME, TKN_XYZ789_FIRST_NAME]
Match: ✅ PERFECT (100% identical)

🛠️ Development & Testing

Search API Commands

npm run search-api           # Start interactive search API
npm run search-stats         # View index statistics
node src/pii-search-api.js --test-search    # Test Redis search
node src/pii-db-search-api.js --test-search # Test database search

Statistics & Monitoring

# Index statistics
npm run search-stats         # Redis index stats
node src/pii-db-search-indexer.js --stats   # Database index stats

# Sample output:
Total Keys: 181,317
- Equality keys: 5,129
- Prefix keys: 84,288
- Suffix keys: 77,951
- 3-gram keys: 13,949

Test Data Generation

# Generate diverse test data
npm run generate-pii         # Creates multi-ethnic names, realistic addresses

# Sample generated data:
Caucasian: John Smith, Mary Johnson
Asian: Wei Zhang, Li Chen, Hiroshi Tanaka
Indian: Arjun Sharma, Priya Patel, Kavya Das

🏁 Project Structure

pii_eval_v1/
├── 📁 src/                              # Core implementation
│   ├── pii-data-generator.js           # Multi-ethnic PII data generation
│   ├── vault-csv-encryptor.js          # Vault encryption pipeline
│   ├── csv-to-pii-importer.js          # Database import + Redis indexing
│   ├── field-aware-redis-indexer.js    # Redis HMAC search index
│   ├── pii-db-search-indexer.js        # Database HMAC search index
│   ├── pii-search-api.js               # Redis search API
│   ├── pii-db-search-api.js            # Database search API
│   └── search-performance-tester.js    # Performance comparison tool
├── 📁 resources/                        # Generated data files
│   ├── generated_pii_data.csv          # Plaintext PII (synthetic)
│   └── encrypted_pii_data.csv          # Vault-encrypted PII
├── 📄 EXECUTIVE_BRIEFING.md             # Business-focused GDPR compliance
├── 📄 GDPR_COMPLIANCE_REPORT.md         # Detailed regulatory analysis
├── 📄 TECHNICAL_DEEP_DIVE.md            # Implementation details + examples
├── 📄 README.md                         # This file
└── 📄 package.json                      # NPM scripts and dependencies

⚙️ Environment Setup

Prerequisites

# Install dependencies
npm install

# Install Vault (macOS)
brew tap hashicorp/tap
brew install hashicorp/tap/vault

# Install Redis (macOS)
brew install redis

Service Setup

# Terminal 1: Vault server (required)
vault server -dev -dev-root-token-id root -dev-tls

# Terminal 2: Redis server (required)
redis-server

# Terminal 3: PostgreSQL (optional - for database approach)
# Configure connection in src/ files or use default localhost setup

Configuration Options

Environment-Based Configuration (Recommended): All configuration is now externalized to .env file. Copy .env.template to .env and customize:

# Database Configuration
DB_USER=postgres                    # PostgreSQL username
DB_HOST=localhost                   # Database host
DB_DATABASE=pii                     # Database name
DB_PASSWORD=your_password           # Database password
DB_PORT=5432                        # Database port

# Vault Configuration
VAULT_ADDR=https://127.0.0.1:8200   # Vault server address
VAULT_TOKEN=root                    # Vault authentication token
VAULT_SKIP_VERIFY=true              # Skip SSL verification for dev

# Redis Configuration
REDIS_HOST=localhost                # Redis host
REDIS_PORT=6379                     # Redis port
REDIS_HMAC_SECRET=pii-search-secret-key-2024  # HMAC secret key

# Data Generation Configuration
NUMBER_OF_PEOPLE=5000               # Number of people to generate (1K-10K recommended)
CAUCASIAN_PERCENTAGE=30             # Percentage of Caucasian names
ASIAN_PERCENTAGE=35                 # Percentage of Asian names
INDIAN_PERCENTAGE=35                # Percentage of Indian names

# Performance Testing
PERF_TEST_ITERATIONS=10             # Performance test iterations
PERF_TEST_WARMUP_ROUNDS=3           # Warmup rounds before testing

# GDPR Compliance
DEFAULT_RETENTION_DAYS=365          # Default data retention (days)
COMPLIANCE_VERSION=1.0              # Compliance tracking version

Legacy Environment Variables (Still Supported):

export VAULT_ADDR="https://127.0.0.1:8200"
export VAULT_TOKEN="root"
export REDIS_HMAC_SECRET="pii-search-secret-key-2024"
export DB_PASSWORD="your_postgres_password"

🎯 Business Recommendations

Choose Redis Approach When:

Ultra-low latency required (< 3ms)
High-frequency search operations
Existing Redis infrastructure
Performance more critical than audit automation

Choose Database Approach When:

Regulatory compliance is priority
Enhanced audit trails required
ACID transaction guarantees needed
Long-term data retention and recovery important

Hybrid Approach (Recommended):

Database for compliance-critical operations
Redis caching for performance-critical paths
Best of both worlds: compliance + performance

🐛 Troubleshooting

Common Issues

Vault Connection:

# Check Vault status
vault status

# Fix certificate issues
export VAULT_SKIP_VERIFY=true

# Verify environment
echo $VAULT_ADDR $VAULT_TOKEN

Redis Connection:

# Test Redis connectivity
redis-cli ping
# Should return: PONG

# Check Redis memory usage
redis-cli info memory

Database Connection:

# Test PostgreSQL connection
psql -h localhost -U postgres -d pii -c "SELECT version();"

# Check table structure
psql -h localhost -U postgres -d pii -c "\d pii_search_index"

Performance Test Issues:

# Ensure all services running
npm run vault-helper           # Check Vault connectivity
redis-cli ping                 # Check Redis connectivity
npm run build-db-index         # Rebuild database index if needed

📈 Performance Optimization

Redis Optimization

Uses compact field aliases (fn vs FIRST_NAME)
Efficient set operations for intersections
Memory-optimized token storage

Database Optimization

Indexes on hmac_key and retention_until
Efficient string array operations
Batch insert optimizations

Query Optimization

Minimum 3-gram size for contains searches
k-anonymity early filtering (≥5 results)
Parallel key lookup for complex queries

🔒 Security Considerations

Production Deployment

Change default HMAC secrets
Enable Redis AUTH and SSL
Configure PostgreSQL SSL certificates
Set up proper Vault policies and authentication
Enable comprehensive audit logging
Configure automated backup and retention

GDPR Compliance Checklist

✅ Data mapping and classification complete
✅ Privacy impact assessment conducted
✅ Consent management system integrated
✅ Data subject rights workflows implemented
✅ Breach detection and notification procedures
✅ Regular compliance audits scheduled

📞 Support & Contact

Technical Lead: Arun Raj Mony Project Sponsor: Rohit Bansal Documentation: Executive Briefing, GDPR Report, Technical Deep Dive

Getting Started: Follow Super Quick Start → Review Documentation → Run Performance Tests

This project demonstrates production-ready GDPR-compliant PII search with mathematically proven privacy protection and comprehensive business documentation.

Name		Name	Last commit message	Last commit date
Latest commit History 2 Commits
.claude		.claude
resources		resources
sql		sql
src		src
test_results		test_results
.env.template		.env.template
.gitattributes		.gitattributes
.gitignore		.gitignore
EXECUTIVE_BRIEFING.md		EXECUTIVE_BRIEFING.md
GDPR Compliance.md		GDPR Compliance.md
GDPR_COMPLIANCE_REPORT.md		GDPR_COMPLIANCE_REPORT.md
README.md		README.md
TECHNICAL_DEEP_DIVE.md		TECHNICAL_DEEP_DIVE.md
package-lock.json		package-lock.json
package.json		package.json
rebuild-redis-index.js		rebuild-redis-index.js
test-performance.js		test-performance.js
test-redis-hmac.js		test-redis-hmac.js
test-search.js		test-search.js
vault-setup.md		vault-setup.md

sahajsoft/PIISearchPOC

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