GALILEO
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Galileo Protocol · MMXXVI

Hybrid Architecture

Galileo uses a hybrid on-chain/off-chain architecture that balances transparency with privacy. This design enables GDPR compliance while maintaining immutable ownership records.

Three-Layer Model


+---------------------------------------------------------+
|                    OFF-CHAIN LAYER                       |
|  +--------------+  +--------------+  +--------------+  |
|  | DPP Storage  |  | EPCIS Events |  |  Personal    |  |
|  | (JSON-LD)    |  |  (History)   |  |    Data      |  |
|  +--------------+  +--------------+  +--------------+  |
|                         ^                               |
|                         | CRAB Model                    |
|                         | (hash anchoring)              |
+---------------------------------------------------------+
|                    RESOLVER LAYER                        |
|  +--------------------------------------------------+   |
|  |              GS1 Digital Link Resolver           |   |
|  |         (Context-Aware Role-Based Access)        |   |
|  +--------------------------------------------------+   |
|                         |                               |
+---------------------------------------------------------+
|                    ON-CHAIN LAYER                        |
|  +--------------+  +--------------+  +--------------+  |
|  |  ERC-3643    |  |  ONCHAINID   |  |  Compliance  |  |
|  |   Tokens     |  |  Registry    |  |   Modules    |  |
|  +--------------+  +--------------+  +--------------+  |
+---------------------------------------------------------+

On-Chain Layer

The on-chain layer stores ownership proofs and compliance state on an EVM blockchain:

  • ERC-3643 Tokens — Ownership records with built-in compliance
  • ONCHAINID Registry — Identity verification claims
  • Compliance Modules — Pluggable transfer rules

On-chain data is public and immutable. It contains NO personal data to ensure GDPR compliance.

Off-Chain Layer

The off-chain layer stores detailed product and personal data:

  • DPP Storage — Digital Product Passport attributes
  • EPCIS Events — Full lifecycle event history
  • Personal Data — Customer information (encrypted, access-controlled)

Off-chain data is deletable, satisfying GDPR right to erasure while maintaining on-chain integrity via content hashes.

Resolver Layer

The GS1 Digital Link resolver bridges physical products to digital records:

  • URI Resolution — Scan QR code to get product data
  • Context-Aware Routing — Different views for different roles
  • Linkset Navigation — Discover related resources

CRAB Model (GDPR Compliance)

Galileo uses the CRAB pattern for GDPR compliance:

  • Claim hash on-chain — Cryptographic anchor only
  • Raw data off-chain — Actual content in compliant storage
  • Access controlled — Role-based permissions
  • Blinded deletion — Remove data while preserving hash proofs

Data Flow Example

When a product is sold:

  1. Buyer's identity is verified via ONCHAINID claims
  2. Compliance modules check transfer rules
  3. Token ownership transfers on-chain
  4. Sale event recorded off-chain (EPCIS)
  5. DPP updated with new owner reference

Further Reading