Overview
The W3C Verifiable Credential (VC) standard provides a framework for creating machine-verifiable, tamper-resistant ITMO (Internationally Transferred Mitigation Outcome) certificates for carbon trading and cross-border climate initiatives. ITMOs are standardized units representing greenhouse gas emission reductions that can be transferred between countries under Article 6.2 of the Paris Agreement. This guide explains how to implement ITMO certificates and use the accompanying JSON-LD context.
Key Benefits
- Cryptographic Trust - Signatures ensure authenticity and detect tampering
- Global Standards - W3C format enables cross-platform compatibility
- Extensible Design - JSON-LD approach allows adding properties without breaking changes
- Privacy Controls - Selective disclosure of sensitive transaction details
- Provenance Tracking - Built-in support for tracking credential history
Schema Structure
Each ITMO credential contains:
{
"@context": ["Base contexts and ITMO context"],
"id": "Unique credential identifier",
"type": ["VerifiableCredential", "ITMOCredential"],
"issuer": "DID of issuing entity",
"issuanceDate": "Issuance timestamp",
"expirationDate": "Expiration timestamp",
"credentialSubject": {
// ITMO-specific data sections
},
"credentialSchema": "Schema reference",
"credentialStatus": "Status information",
"evidence": "Supporting documentation",
"proof": "Cryptographic proof"
}
The credentialSubject
contains four main ITMO-specific sections:
authorizationInfo
- Authorization details and participating parties
ndcQuantification
- NDC sectors, sources, and GHG information
correspondingAdjustments
- Adjustment calculations and emissions data
environmentalIntegrity
- Environmental integrity metrics and compliance
JSON-LD Context
Setup
Add the ITMO and required contexts to your credential:
{
"@context": [
"https://www.w3.org/2018/credentials/v1",
"https://w3id.org/security/suites/ed25519-2018/v1",
{
"itmo": "https://w3id.org/article6/itmo-context.jsonld",
"prov": "http://www.w3.org/ns/prov#"
}
]
}
Core Properties
The ITMO context defines these key sections:
authorizationReference
- Reference ID for the authorization
cooperativeApproachDuration
- Time period of the approach
expectedMitigationOutcomes
- Expected outcomes by year
participatingParties
- List of participating countries
authorizedEntities
- List of authorized entity DIDs
NDC Quantification
ndcSectors
- Covered sectors (e.g., “Residential”)
ndcSources
- Emission sources
ndcGHGs
- Covered greenhouse gases
ndcTimePeriods
- Relevant time periods
ndcReferenceLevel
- Reference emission levels
ndcTargetLevel
- Target emission levels
Corresponding Adjustments
singleYearNDC
- Single year NDC flag
multiYearNDC
- Multi year NDC flag
emissionsTrajectory
- Emissions trajectory data
annualCorrespondingAdjustments
- Annual adjustment values
averageAnnualITMOs
- Average annual ITMO amount
cumulativeAdjustments
- Cumulative adjustment total
Environmental Integrity
environmentalIntegrityMetrics
- Used metrics (e.g., “CO2e”)
ipccMethodologiesReference
- IPCC methodology reference
partyStatusUnderParis
- Paris Agreement status
trackingArrangements
- Links to tracking systems
mostRecentNationalInventory
- Latest inventory reference
Implementation Example
Here’s a minimal example of creating an ITMO credential:
{
"@context": [
"https://www.w3.org/2018/credentials/v1",
"https://w3id.org/security/suites/ed25519-2018/v1",
{
"itmo": "https://w3id.org/article6/itmo-context.jsonld",
"prov": "http://www.w3.org/ns/prov#"
}
],
"type": ["VerifiableCredential", "ITMOCredential"],
"issuer": "did:example:issuer",
"issuanceDate": "2024-03-15T00:00:00Z",
"credentialSubject": {
"id": "did:example:subject",
"itmo:authorizationInfo": {
"itmo:authorizationReference": "AUTH-2024-001",
"itmo:participatingParties": ["Country A"],
"itmo:expectedMitigationOutcomes": {
"2024": 5000
}
}
}
}
Validation Requirements
Technical checks:
- JSON-LD context validation
- Schema conformance
- Cryptographic proof verification
- Credential status verification
Business rules:
- Required ITMO fields present
- Valid participating parties
- Environmental integrity compliance
- NDC alignment verification
Security and Privacy
Security Best Practices
- Use Ed25519 signatures for proofs
- Implement proper key management
- Regular credential status updates
- Monitor for revoked credentials
Privacy Guidelines
- Enable selective disclosure of sensitive data
- Implement minimal disclosure principle
- Define clear data retention policies
- Comply with relevant privacy regulations
Resources
Responses are generated using AI and may contain mistakes.