🧠 Use Case

Design a blockchain-based aid delivery system to verify eligibility, issue traceable payments (or vouchers), and audit aid impact in crisis zones — including refugee camps, natural disasters, or food insecurity regions.

The system ensures that:

• Only verified individuals receive aid.
• Disbursements are logged immutably.
• Aid eligibility persists post-crisis as a digital asset for recovery or follow-up services.

1. 🔁 Functional Architecture Overview

[NGO Registers Beneficiary]

↓

[VC Issued (Eligibility Claim)]

↓

[Beneficiary Wallet (PWA / SMS / Lace)]

↓

[Smart Contract (Disbursement Logic)]

↓

[Aid (e.g. USDA) Sent + Metadata Logged]

↓

[Donor/Aid Dashboard → TX Log via Koios]

↓

[Beneficiary Retains Identity for Future Access]

🧑 Actors:

• NGO or Field Agent – Issues the VC
• Beneficiary – Receives aid, stores credentials
• Smart Contract – Releases funds if VC hash is valid and within aid window
• Public Verifier – Monitors disbursements via dashboards

2. 📄 Verifiable Credential (VC) for Aid Eligibility

📁 vc-schema/aid-eligibility.json

{

"@context": ["<https://www.w3.org/2018/credentials/v1>"],

"type": ["VerifiableCredential", "AidEligibilityCredential"],

"issuer": "did:cardano:ngo123",

"issuanceDate": "2025-05-01T00:00:00Z",

"credentialSubject": {

"id": "did:cardano:beneficiary123",

"eligibility": "YES",

"location": "Zaatari Camp, Jordan",

"familySize": 6,

"aidType": "Shelter & Food"

},

"proof": {

"type": "Ed25519Signature2020",

"created": "2025-05-01T00:00:00Z",

"proofPurpose": "assertionMethod",

"verificationMethod": "did:cardano:ngo123#key-1",

"jws": "eyJhbGciOiJFZERTQSJ9..."

}

}

⚠️ This VC is validated off-chain. Only the hash of credentialSubject is used in smart contract logic.

3. 🔐 VC Hashing (Credential Anchoring)