did:grn

Grano DID Method (did:grn) is a decentralized identifier implementation built on the Grano blockchain network. This method provides a way to create and manage decentralized identifiers without requiring explicit registration transactions, making it lightweight and efficient. The system uses secp256k1 cryptography and leverages the Grano blockchain's smart contract capabilities for identity management.

The core functionality revolves around Grano addresses which serve as the foundation for DIDs. Each DID is automatically associated with a default DID Document containing basic verification capabilities. The method supports controller management, allowing identity owners to transfer control of their DIDs to different addresses, and provides attribute management for adding services and verification methods.

Key features include:

• Implicit Registration - No blockchain transaction needed for initial DID creation
• Smart Contract Events for tracking DID document changes
• Attribute System for extensible identity information
• Controller Transfer capabilities
• Service Endpoint management
• Deactivation Support through null address controllers

The method specifically avoids storing personal information on-chain and focuses on maintaining only public keys, service endpoints, and control relationships. This approach aligns with privacy best practices while providing robust identity management capabilities.

Technical Implementation:

1. DID Generation and Structure

• Format: did:grn:<grano-address>
• grano-address = grano1 + 38*HEXDIG
• Based on secp256k1 key pairs
• Default DID document automatically available upon creation

2. Resolution Process

• Utilizes read-only functions on the Grano registry
• Processes two main event types:
  • DIDControllerChanged
  • DIDAttributeChanged
• Resolution includes:
  • Checking controller status
  • Building verification methods
  • Compiling service endpoints
  • Validating attribute timestamps

3. Key Management and Security

• Implements EcdsaSecp256k1RecoveryMethod2020
• Supports multiple verification relationships
• Controller address management
• Attribute-based key management
• Revocation through controller nullification

4. Technology Stack

• Grano Blockchain infrastructure
• CosmWasm smart contracts
• Event-driven state management
• W3C DID specification compliance
• JSON-LD context support

5. Unique Characteristics

• Event-based DID document construction
• Implicit registration model
• Attribute expiration support
• Strict separation of on-chain/off-chain data
• Controller-based deactivation mechanism