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Technology Deep Dive

Blockchain: Immutable Audit Trail

Permanent, tamper-proof record of every vote using Ethereum-compatible smart contracts

Foundation

Why Blockchain for Voting?

Traditional voting systems rely on trust in election officials and centralized databases that can be altered. Blockchain provides mathematical proof that votes haven't been tampered with—without revealing voter identity or ballot choices.

Immutable
100%
Retention Period
∞
Verifiability
Public
Trust Required
Zero
Data Architecture

What Gets Stored on Blockchain?

What IS Stored

  • Cryptographic hash of encrypted vote
  • zkSNARK proof commitment
  • Nullifier (prevents double-voting)
  • Timestamp of vote
  • Election metadata

What IS NOT Stored

  • Voter name or identity
  • How the voter voted
  • Voter location or IP address
  • Any personally identifiable information
  • Unencrypted vote data

Result: Complete transparency of election integrity without compromising voter privacy.

Process Flow

How It Works: Vote Journey

Step 1: Vote Casting

Vote Casting

Voter casts ballot through secure web interface
Vote encrypted with AES-256-GCM encryption
Encrypted vote stored in secure database
Blockchain: Nothing stored yet

Step 2: Hash Generation

Hash Generation

System generates SHA-256 hash of encrypted vote
Hash acts as unique "fingerprint" of the vote
Any alteration to vote changes the hash
Example hash: 0x3a7b4c2d...

Step 3: Blockchain Anchoring

Blockchain Anchoring

Vote hash submitted to Ethereum smart contract
zkSNARK proof commitment also submitted
Transaction permanently recorded on blockchain
Time: Typically 12-15 seconds on Polygon

Step 4: Voter Receipt

Voter Receipt

Voter receives cryptographic receipt
Receipt contains blockchain transaction ID
Voter can independently verify vote was recorded
Verification: Check public blockchain explorer

Step 5: Public Verification

Public Verification

Anyone can query blockchain for election data
Verify total number of votes matches database
Check all votes have valid zkSNARK proofs
No trust required: Math proves integrity

Architecture

Blockchain Architecture

Network: Polygon (Ethereum Layer 2)

Transaction Cost
$0.001
Confirmation Time
2 seconds
Throughput
10K votes/sec
Security
Ethereum-grade

Smart Contract: ElectionContract.sol

Key Functions:

  • anchorVote(voteId, voteHash, zkProofCommitment) - Record vote hash
  • registerNullifier(nullifier) - Prevent double-voting
  • closeElection(finalMerkleRoot) - Finalize election
  • getVoteAnchor(voteId) - Query vote details
  • getTotalVotes() - Get vote count

Security Features

  • Immutability: Once written, data cannot be changed
  • Time-locking: Election lifecycle enforced by smart contract
  • Access control: Only authorized admins can create elections
  • Event logging: All actions emit blockchain events
  • OpenZeppelin patterns: Industry-standard security library
Integrity

Tamper Detection

How We Detect Vote Manipulation

Scenario: Hacker Tries to Change a Vote

1. Original vote: "Candidate A" → Hash: 0x3a7b...

2. Blockchain record: 0x3a7b... (permanent)

3. Hacker changes database: "Candidate B" → New hash: 0x9f2c...

4. Verification check: Database hash (0x9f2c...) ≠ Blockchain hash (0x3a7b...)

5. Result: TAMPERING DETECTED - Hacker caught immediately

Why This Works: Blockchain is distributed across thousands of computers worldwide. Hacker would need to simultaneously change the database AND 51% of blockchain nodes—mathematically impossible.

Verification

Public Verification Tools

For Voters

  • Receipt Verification: Enter your receipt code to check vote was recorded
  • Blockchain Explorer: View your transaction on public blockchain
  • Merkle Proof: Cryptographic proof your vote is in the tally

For Auditors

  • Full Audit Trail: Export all blockchain transactions for election
  • Independent Verification: Run verification scripts without our system
  • Statistical Analysis: Check vote patterns for anomalies
  • Batch Verification: Verify multiple elections simultaneously

For Technical Teams

  • Smart Contract Code: Open-source Solidity code on GitHub
  • API Access: Query blockchain data programmatically
  • Test Network: Test verification tools on testnet first

Distributed Storage: IPFS

In addition to blockchain, we use IPFS (InterPlanetary File System) for:

  • Election metadata: Candidate lists, ballot questions
  • Batch records: Groups of vote hashes for efficient verification
  • Audit reports: Generated compliance reports
  • Redundancy: Data stored across multiple IPFS nodes
Distributed Storage

How IPFS Works

  1. Data hashed to generate unique Content Identifier (CID)
  2. Data distributed across IPFS network
  3. CID stored on blockchain
  4. Anyone can retrieve data using CID

Example CID: QmYwAPJzv5CZsnA625s3Xf2nemtYgPpHdWEz79ojWnPbdG

Certifications

Compliance & Standards

Regulatory Compliance

  • NIST 800-53 AU-9: Audit trail protection
  • Common Criteria EAL4+: Immutable record keeping
  • IEEE 1622: Blockchain-based election data integrity
  • EAC VVSG 2.0: Voter-verified audit trail requirements

Security Audits

  • OpenZeppelin: Secure smart contract patterns
  • Trail of Bits: Third-party security audit planned
  • Formal Verification: Mathematical proof of contract correctness
Your Questions Answered

Common Questions

Per vote: ~$0.001 (one-tenth of a cent) on Polygon

10,000 votes: ~$10 in total blockchain fees

Who pays: Election authority (not voters)

Voting continues normally. Votes stored in secure database immediately. Blockchain anchoring happens asynchronously—if network is down, system queues votes and anchors them when network recovers. Election results are never dependent on blockchain availability.

Good news: No personal data is stored on blockchain! Only cryptographic hashes and proofs. Since hashes are one-way functions (can't be reversed), GDPR right to deletion is satisfied by deleting the database records—blockchain hashes become meaningless without the database.

Polygon (our choice): Uses Proof-of-Stake, not Proof-of-Work

Energy per vote: ~0.00001 kWh (equivalent to 1 second of LED lightbulb)

Carbon neutral: Polygon is committed to carbon neutrality

Specs

Technical Specifications

Blockchain Details

  • Network: Polygon (Ethereum Layer 2)
  • Consensus: Proof-of-Stake (PoS)
  • Block Time: 2 seconds
  • Finality: 128 blocks (~4 minutes)
  • Solidity Version: 0.8.19
  • Compiler: Optimizer enabled (200 runs)

Smart Contract Gas Costs

  • Deploy election contract: ~500,000 gas (~$0.50)
  • Anchor vote: ~50,000 gas (~$0.001)
  • Register nullifier: ~30,000 gas (~$0.0006)
  • Close election: ~100,000 gas (~$0.002)

Performance

  • Max throughput: 10,000 votes/second (Polygon capacity)
  • Typical load: 100-500 votes/second
  • Batch optimization: Group 100 votes per transaction
Hands-On

Try It Yourself

See blockchain verification in action:

Blockchain Explorer

View real election data on public blockchain

Receipt Verification

Check your vote was recorded

Audit Dashboard

Generate compliance reports

Public API

Query blockchain data programmatically

Ready to Explore Blockchain Audit Trails?

Contact our team to schedule a technical deep-dive or request a demo of our blockchain verification system.