# WIA-SOC-015: Phase 3 - Verification Protocol Specification

**Version:** 1.0  
**Status:** FINAL  
**Last Updated:** 2025-01-15  
**Standards Body:** World Certification Industry Association (WIA)

---

## 1. Overview

Phase 3 defines cryptographic protocols enabling end-to-end verifiable voting while maintaining ballot secrecy. This specification covers voter authentication, ballot encryption, blockchain integration, and zero-knowledge proofs.

---

## 2. Voter Authentication

### 2.1 Multi-Factor Authentication

Minimum two of three factor types required:
- **Something You Know:** Password, PIN, security questions
- **Something You Have:** Smart card, mobile device, hardware token
- **Something You Are:** Fingerprint, facial recognition, iris scan

### 2.2 Biometric Authentication

Supported modalities:
- Fingerprint (99.9% accuracy requirement)
- Facial recognition (99.5% accuracy requirement)
- Iris scan (99.99% accuracy requirement)
- Voice recognition (98% accuracy requirement)

**Privacy Protection:**
- Biometric templates stored as one-way hashes
- No raw biometric images retained
- Templates cannot be reverse-engineered

---

## 3. Ballot Encryption

### 3.1 Homomorphic Encryption

Approved cryptosystems:
- ElGamal (2048-bit minimum)
- Paillier (3072-bit minimum)

**Security Requirement:** Minimum 256-bit security strength

### 3.2 Encryption Process

1. Voter casts ballot
2. Ballot encrypted with election public key
3. Voter signs encrypted ballot with private key
4. Signed encrypted ballot stored
5. Receipt generated for voter verification

---

## 4. Blockchain Integration

### 4.1 Immutable Audit Trail

Every election event recorded on permissioned blockchain:
- Voter registration events
- Ballot cast events
- Vote tabulation events
- Audit access events

### 4.2 Smart Contract Requirements

```solidity
contract Election {
  mapping(address => bool) hasVoted;
  mapping(bytes32 => uint) voteCounts;
  
  function castVote(bytes32 ballotHash, bytes signature) public {
    require(!hasVoted[msg.sender], "Already voted");
    require(verifySignature(ballotHash, signature), "Invalid signature");
    require(block.timestamp < votingDeadline, "Voting period ended");
    
    hasVoted[msg.sender] = true;
    emit VoteCast(msg.sender, ballotHash, block.timestamp);
  }
}
```

---

## 5. Zero-Knowledge Proofs

### 5.1 zk-SNARKs Implementation

- **Proving System:** Groth16
- **Security Level:** 128-bit
- **Proof Size:** <200 bytes
- **Verification Time:** <5ms

### 5.2 Proof Types

- **Proof of Ballot Validity:** Ballot is well-formed
- **Proof of Inclusion:** Ballot included in final tally
- **Proof of Correct Tabulation:** Results accurately reflect ballots

---

## 6. Key Management

### 6.1 Key Generation Ceremony

Public ceremony with multiple independent trustees:
1. Public announcement with observer invitations
2. Each trustee generates key share independently
3. Shares combined using threshold cryptography
4. Public key published and signed by all trustees

### 6.2 Decryption Ceremony

Results decrypted through public ceremony:
1. Encrypted ballots finalized and hashed
2. Threshold trustees convene publicly
3. Each trustee applies key share
4. Results fully decrypted when threshold reached

---

## 7. Integrity Protection

### 7.1 Tamper Detection

- Cryptographic hashes detect data modification
- Digital signatures verify authenticity
- Blockchain immutability prevents historical changes
- Hardware security modules protect cryptographic operations

### 7.2 Coercion Resistance

- Receipt-free voting
- Fake credential generation capability
- Revote options during voting period
- Vote cancellation through secure process

---

**© 2025 World Certification Industry Association (WIA)**  
**弘益人間 (Hongik Ingan) - Benefit All Humanity**