GDPR Compliance

Overview

Anchora is designed to help you maintain GDPR compliance while leveraging blockchain technology for data integrity. This guide explains how Anchora handles personal data and provides tools to meet your regulatory obligations.

GDPR Key Concepts

Understanding these GDPR concepts is essential when using Anchora:

Data Architecture for GDPR

Anchora uses a separation of concerns architecture that allows you to delete personal data while maintaining proof of integrity.

The Hash-Only Approach

Instead of storing personal data with Anchora, store only the cryptographic hash. This approach provides:

• Blockchain proof that data existed at a specific time
• No personal data stored on our servers or the blockchain
• Full ability to delete the source data on your systems

const crypto = require('crypto');

// Hash the personal data locally
const userData = {
  name: 'John Doe',
  email: 'john@example.com',
  dateOfBirth: '1990-01-15'
};

const hash = crypto
  .createHash('sha256')
  .update(JSON.stringify(userData))
  .digest('hex');

// Send data to hash-only endpoint (data is hashed and discarded)
const response = await fetch('https://api.anchora.co.in/v1/anchor/hash', {
  method: 'POST',
  headers: {
    'Authorization': `Bearer ${apiKey}`,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    data: userData,
    metadata: {
      type: 'user_consent',
      userId: 'internal_ref_123'  // Non-PII reference
    }
  })
});

Right to Erasure Implementation

When a user requests deletion, you need to handle both your internal data and Anchora records.

Soft Delete

Soft delete marks the record as deleted but preserves the blockchain proof. The data payload is removed, but the hash remains.

curl -X DELETE https://api.anchora.co.in/v1/records/507f1f77bcf86cd799439011 \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "mode": "soft"
  }'

Hard Delete

Hard delete removes all record data from Anchora's servers. The blockchain transaction remains (hashes only, no personal data).

curl -X DELETE https://api.anchora.co.in/v1/records/507f1f77bcf86cd799439011 \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "mode": "hard",
    "encryptionKey": "your-32-char-minimum-encryption-key-here"
  }'

Data Portability with Search

Use the search API to find all records associated with a user to fulfill data portability requests.

curl -X POST https://api.anchora.co.in/v1/records/search \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "field": "email",
    "value": "john@example.com",
    "page": 1,
    "limit": 50
  }'

Search Response

{
  "success": true,
  "records": [
    {
      "recordId": "507f1f77bcf86cd799439011",
      "hash": "a1b2c3d4e5f6...64chars",
      "status": "ANCHORED",
      "createdAt": "2025-12-03T10:00:00.000Z",
      "anchoredAt": "2025-12-03T10:01:30.000Z"
    }
  ],
  "pagination": {
    "page": 1,
    "limit": 50,
    "totalRecords": 1,
    "totalPages": 1,
    "hasNextPage": false
  }
}

Processing Records

Maintain a record of processing activities using Anchora.

curl -X POST https://api.anchora.co.in/v1/anchor \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "data": {
      "action": "consent_given",
      "purposes": ["marketing", "analytics"],
      "method": "web_form",
      "ipHash": "a1b2c3...",
      "timestamp": "2024-01-31T10:30:00Z"
    },
    "metadata": {
      "userId": "user_12345",
      "type": "gdpr_consent"
    }
  }'

Data Processing Agreement

Anchora acts as a data processor under GDPR. Key provisions in our DPA include:

• Purpose limitation: Data processed only for anchoring services
• Sub-processors: AWS (EU region), Polygon blockchain
• Security measures: Encryption at rest and in transit
• Breach notification: Within 24 hours of discovery
• Data location: EU data centers available on Enterprise plans

Best Practices

• Use hash-only mode: When possible, hash data locally and only send hashes to Anchora
• Implement retention policies: Set automatic expiry on all records containing personal data
• Document your processing: Anchor consent records and processing activities
• Plan for deletion: Design your data model to support granular deletion
• Use pseudonymization: Replace direct identifiers with internal references
• Encrypt sensitive data: Use client-side encryption for additional protection

Compliance Checklist