# WIA-EDU-011 Digital Credential Standard v1.0

## Phase 1: Data Format & Structure

**Status:** ✅ Complete
**Version:** 1.0.0
**Date:** 2025-01-15
**Philosophy:** 弘益人間 (Benefit All Humanity)

---

## 1. Overview

This specification defines the foundational data format and structure requirements for WIA-compliant digital credentials. Phase 1 establishes W3C Verifiable Credentials as the mandatory format with comprehensive metadata, cryptographic proofs, and blockchain anchoring.

## 2. Scope

Phase 1 covers:
- Credential data format (W3C VC)
- Metadata schemas
- Cryptographic proof requirements
- Decentralized Identifiers (DIDs)
- Credential types and classifications
- Privacy and security requirements

## 3. W3C Verifiable Credentials Requirements

### 3.1 Base Format

All digital credentials MUST conform to W3C Verifiable Credentials Data Model 2.0 specification.

**Mandatory Components:**
- `@context` array with proper context URLs
- Unique credential `id` using DID method
- `type` array including `VerifiableCredential`
- `issuer` object with valid DID
- `issuanceDate` in ISO 8601 format
- `credentialSubject` with holder information
- Cryptographic `proof` object

### 3.2 Credential Structure

```json
{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://wia.org/credentials/education/v1"
  ],
  "id": "did:wia:edu:mit:degree:12345",
  "type": ["VerifiableCredential", "EducationCredential"],
  "issuer": {
    "id": "did:wia:edu:mit",
    "name": "Massachusetts Institute of Technology",
    "type": "EducationalOrganization",
    "url": "https://mit.edu"
  },
  "issuanceDate": "2024-06-15T00:00:00Z",
  "expirationDate": "2099-12-31T23:59:59Z",
  "credentialSubject": {
    "id": "did:wia:student:alice",
    "type": "Student",
    "name": "Alice Johnson",
    "achievement": {
      "type": "BachelorDegree",
      "name": "Bachelor of Science in Computer Science",
      "field": "Computer Science",
      "level": "Undergraduate",
      "gpa": "3.85",
      "graduationDate": "2024-06-15",
      "honors": "Magna Cum Laude"
    }
  },
  "proof": {
    "type": "Ed25519Signature2020",
    "created": "2024-06-15T12:00:00Z",
    "verificationMethod": "did:wia:edu:mit#key-1",
    "proofPurpose": "assertionMethod",
    "proofValue": "z58DAdFfa9SkqZMVPxAQp...Wn1AKYYzBTFJM"
  }
}
```

## 4. Credential Types

### 4.1 Education Credential Types

**Degrees:**
- BachelorDegree
- MasterDegree
- DoctoralDegree
- AssociateDegree

**Certificates:**
- ProfessionalCertificate
- CompletionCertificate
- TrainingCertificate
- MicroCredential

**Diplomas:**
- HighSchoolDiploma
- UniversityDiploma

**Transcripts:**
- AcademicTranscript
- CourseCompletionRecord

## 5. Decentralized Identifiers (DIDs)

### 5.1 DID Requirements

All parties MUST use DIDs conforming to W3C DID Core specification:

**Issuer DID Format:**
```
did:wia:edu:{institution-identifier}
Example: did:wia:edu:mit
```

**Student DID Format:**
```
did:wia:student:{unique-identifier}
Example: did:wia:student:alice123
```

### 5.2 DID Methods

Supported DID methods:
- `did:wia` (WIA proprietary method)
- `did:ethr` (Ethereum-based)
- `did:web` (Web-based)
- `did:key` (Static cryptographic keys)

## 6. Cryptographic Proofs

### 6.1 Signature Algorithms

**Mandatory Support:**
- Ed25519Signature2020
- EcdsaSecp256k1Signature2019

**Optional Support:**
- RsaSignature2018
- JsonWebSignature2020

### 6.2 Proof Structure

```json
{
  "type": "Ed25519Signature2020",
  "created": "2024-06-15T12:00:00Z",
  "verificationMethod": "did:wia:edu:mit#key-1",
  "proofPurpose": "assertionMethod",
  "proofValue": "z58DAdFfa9SkqZMVPxAQp...Wn1AKYYzBTFJM"
}
```

## 7. Metadata Requirements

### 7.1 Educational Metadata

**Degree Credentials MUST include:**
- Degree type and level
- Field of study
- Major and minor (if applicable)
- GPA or grade classification
- Graduation date
- Honors or distinctions
- ISCED level code
- EQF/NQF level (if applicable)

### 7.2 Institution Metadata

**Issuer information MUST include:**
- Official institution name
- DID
- Country code (ISO 3166-1)
- Accreditation information
- Website URL
- Logo URL (optional)

## 8. Privacy and Security

### 8.1 Personal Data Minimization

- Credentials SHOULD contain minimal personal information
- Selective disclosure MUST be supported
- Zero-knowledge proofs SHOULD be supported

### 8.2 Sensitive Information

**Personal data to minimize:**
- Student ID numbers
- Birth dates
- Social security numbers
- Home addresses

**On-chain data restrictions:**
- NO personal data on blockchain
- Only cryptographic hashes
- Timestamps and metadata only

## 9. File Formats and Encoding

### 9.1 JSON-LD

- UTF-8 encoding REQUIRED
- Compact JSON-LD format preferred
- Indentation: 2 spaces (for readability)

### 9.2 Alternative Formats

**Supported export formats:**
- JSON-LD (primary)
- JWT (JSON Web Token)
- QR Code (with embedded JSON-LD)
- PDF with embedded VC

## 10. Validation Requirements

### 10.1 Structural Validation

Credentials MUST validate against:
- JSON Schema for VC Data Model
- WIA-EDU-011 specific schemas
- Context document requirements

### 10.2 Cryptographic Validation

- Signature MUST be verifiable
- Verification method MUST be resolvable
- Proof purpose MUST match use case

## 11. Internationalization

### 11.1 Language Support

- Credentials MAY include multiple language versions
- `language` property in `@context`
- Translate-able fields: name, description, field of study

### 11.2 Character Encoding

- UTF-8 REQUIRED for all text
- Support for all Unicode characters
- Proper handling of right-to-left scripts

## 12. Compliance

Phase 1 credentials MUST comply with:
- ✅ W3C Verifiable Credentials Data Model 2.0
- ✅ W3C DID Core 1.0
- ✅ ISO/IEC 18013-5 (Mobile driving license)
- ✅ GDPR (General Data Protection Regulation)
- ✅ FERPA (Family Educational Rights and Privacy Act)

## Appendix A: Example Credentials

See `/examples` directory for complete credential examples.

## Appendix B: JSON Schema

Complete JSON Schema available at:
https://wia.org/schemas/edu-011/v1.0/credential.json

---

**Philosophy:** 弘益人間 (Benefit All Humanity)

*WIA-EDU-011 Digital Credential Standard*

© 2025 MIT License