Platform / Chain of Custody
The traceability model.
Co2Pathio's chain-of-custody model applies the same cryptographic linking principle used in pharmaceutical supply chain audits and financial settlement trails — but designed for the specific evidence requirements of voluntary carbon registries.
The Chain Model
Each event is a link. Each link references the previous.
A custody chain is a sequence of signed custody records, where each record contains a cryptographic hash of the record before it. Any modification to any record downstream invalidates the entire chain — making tampering structurally detectable, not just auditorially detectable.
// Simplified chain record structure
{
"custody_record": {
"record_id": "CR-2025-VCS-0041872",
"event_type": "REGISTRY_SUBMISSION",
"timestamp": "2025-03-14T09:22:11Z",
"credit_serial": "VCS-REDD-AGB-004187-2025",
"prior_hash": "a7f4c8...3e91d2",
"record_hash": "b9d2e1...7f44ac"
}
}Illustrative record structure. Actual schema includes methodology fields, validator signatures, and standard-specific coverage attestations.
Custody Events
Seven recognized custody event types.
Measurement Receipt
Provider dataset signature logged. Establishes the chain's origin record. Provider identity and dataset provenance are part of the hash input.
Validation Completion
Six-step validation pipeline output committed. Each validation sub-result is included in the hash. Partial validation is structurally distinguishable from complete validation.
Registry Submission
Submission confirmation from registry API appended. Registry identifier and submission timestamp become part of the custody record.
Credit Issuance
Registry-assigned serial number appended to chain. The credit is now traceable from serial number back to originating measurement dataset.
Transfer of Title
Buyer identity (hashed) and transfer date appended. Each transfer event extends the chain without breaking prior links.
Retirement
Final custody event. Retirement confirmation from registry appended. Credit is permanently locked — no further transfer events are valid after retirement.
Verify a credit's chain now.
Enter any Co2Pathio-traced credit serial number to inspect its full custody chain.