did:elastos

The did:elastos method is a blockchain-based DID method developed by the Elastos Foundation that leverages the Elastos ID Sidechain for decentralized identity management.

This method provides self-sovereign identity capabilities where DIDs are fully controlled by their owners without relying on centralized authorities. The system uses the security guarantees of the Elastos blockchain through merged mining with Bitcoin.

Key features include:

• Decentralized Storage on the Elastos ID Sidechain
• Delegated Recovery mechanism allowing trusted third parties to help recover/deactivate compromised DIDs
• Verifiable Credentials support for optional public identity information
• Service Endpoint discovery for identity-related services
• Key Management with support for multiple keys and authentication methods

The method implements:

• create, update and deactivate operations for DID lifecycle management
• Proof-based verification using ECDSAsecp256r1 signatures
• Expiration dates with maximum 5-year validity
• Privacy-preserving design that separates identity claims from DID Documents

Technical Implementation:

1. DID Structure:

• Format: did:elastos:<idstring>
• idstring is a Base58-encoded ID Sidechain address starting with "i"

2. DID Document:

• Uses JSON format (not JSON-LD)
• Contains mandatory id, publicKey, expires and proof properties
• Supports optional authentication, authorization, service and verifiableCredential properties

3. Key Management:

• Requires at least one master public key corresponding to the DID
• Supports multiple additional keys for different purposes
• Implements delegation through authorized recovery keys

4. Resolution:

• Performed by DID Resolver components
• Reads and verifies transactions from ID Sidechain
• Returns normalized DID Documents conforming to W3C DID specification

5. Security:

• Leverages blockchain security through merged mining
• Implements strict operation controls to prevent unauthorized modifications
• Supports key recovery through trusted delegates

The underlying technology stack includes:

• Elastos ID Sidechain for DID storage and operations
• Bitcoin merged mining for security
• ECDSAsecp256r1 for cryptographic operations
• SPV clients for resolution
• JSON for data formatting