PRIVØRA

Private capital for public impact.

A privacy-preserving philanthropy platform that enables anonymous donors to fund verified-but-pseudonymous builders through shielded Zcash transactions, coordinated on NEAR, with zero-knowledge proofs ensuring credibility without identity leakage.

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The Problem: Why Privacy Matters in Philanthropy

In an era where financial surveillance is ubiquitous and political repression targets dissidents through their funding sources, traditional philanthropy platforms create a dangerous paper trail. When an activist building anti-censorship tools receives funding, that transaction—visible on public blockchains or traditional payment rails—becomes a liability. Authoritarian regimes can trace funding networks, identify supporters, and target both donors and recipients.

Privora solves this by architecting a three-layer privacy stack:

1. Payment Layer (Zcash): Shielded transactions where amounts, senders, and recipients are encrypted using zk-SNARKs
2. Coordination Layer (NEAR): Smart contracts that orchestrate matching and impact tracking without storing sensitive data
3. Identity Layer (Zero-Knowledge Proofs): Credibility verification without identity revelation—prove you're human, prove you're a Network School member, prove your location—without revealing which human, which cohort, or where exactly

This isn't just privacy theater. It's a cryptographic guarantee that enables high-risk philanthropy to exist in hostile environments.

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Architecture: Separation of Concerns for Maximum Privacy

Privora follows a layered architecture where each component handles exactly one concern, allowing us to reason about privacy guarantees without hand-waving.

Complete workflow showing the privacy-preserving donation flow from intent to impact

Layer 1: Zcash Payment Layer

All donations flow through Zcash shielded addresses (Z-addresses). The Zcash protocol uses zk-SNARKs to encrypt transaction amounts, sender addresses, and recipient addresses on-chain. Only the parties involved can decrypt their own transactions; to external observers, the blockchain shows only encrypted blobs.

Technical Implementation:

• Shielded address generation for both donors and recipients
• Transaction quotes and status polling for asynchronous settlement
• No on-chain storage of Zcash transaction IDs (preserves privacy)

Layer 2: NEAR Coordination Layer

NEAR smart contracts handle:

• Donor intent matching: Encrypted preference signals matched against pseudonymous profiles
• IPFS persona indexing: On-chain registry of IPFS CIDs (content-addressed profiles)
• Impact SBT minting: FHE-enabled Soulbound Tokens that prove impact without revealing amounts

Key Contracts:

• PersonaRegistry.sol: Minimal on-chain index of IPFS personas (Sepolia)
• ImpactSBT.sol: FHE-enabled SBT contract tracking funded builders and amounts (Sepolia)
• NetworkSchoolVerifier.sol: FHE-based residency verification (Fhenix/CoFHE)

Privacy Guarantee: Only hashes, boolean flags, and encrypted fields are stored on-chain. No PII, no payment amounts (in cleartext), no transaction links.

Layer 3: Zero-Knowledge Identity Layer

Builders prove credibility through multiple ZK proof systems:

• Reclaim Protocol: ZK proofs for GitHub contributions, Leetcode activity, Scholar profiles, and location verification
• Network School Verification: FHE-based proof of Network School residency without revealing cohort
• Future: Semaphore-style proofs for other startup societies (YC, Antler, The Residency)

NEAR AI Integration: PII stripping and persona matching using NEAR AI Cloud, with prompts designed to remove identifying information while preserving semantic meaning for matching.

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Technical Stack

Frontend

• Framework: Next.js 14.2.4 (App Router)
• React: 18.2.0
• Styling: Tailwind CSS with custom matrix theme
• Animations: Framer Motion
• Wallet Integration:
  • Thirdweb SDK (@thirdweb-dev/react) for EVM wallet connection (MetaMask, Rabby, Talisman, etc.)
  • Ethers.js v5.8.0 for contract interactions
• State Management: React Query (TanStack Query v4)
• ZK Proofs: Reclaim Protocol JS SDK

Smart Contracts

• Language: Solidity ^0.8.25
• Networks:
  • Ethereum Sepolia (persona registry, impact SBTs)
  • Fhenix (FHE-enabled Network School verification)
• Libraries:
  • OpenZeppelin Contracts (Ownable, ECDSA)
  • Fhenix CoFHE Contracts (FHE encryption)
• Development: Hardhat with CoFHE plugin

Infrastructure

• IPFS: Profile storage (Pinata/Web3.Storage compatible)
• NEAR AI: PII stripping and persona matching via API proxy
• Zcash: QR payment through Zashi wallet

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Smart Contract Details

PersonaRegistry (Sepolia)

Minimal on-chain index storing only IPFS CIDs. No PII, no profiles, just content-addressed references.

struct Persona {
    address owner;
    string ipfsHash;  // IPFS CID
    uint256 createdAt;
}

Functions:

• registerMyPersona(string ipfsHash): Register your persona's IPFS hash
• getAllPersonas(): Enumerate all registered personas
• getPersonasByOwner(address): Query personas by owner address

ImpactSBT (Sepolia)

FHE-enabled Soulbound Token tracking funding without revealing amounts publicly.

struct Impact {
    address donor;
    string builderPseudonym;
    string causeTag;
    string memo;
    uint256 issuedAt;
    euint128 amountEnc;      // FHE-encrypted amount in zatoshis
    ebool verifiedEnc;       // FHE-encrypted verification flag
}

Privacy Features:

• Amounts encrypted using FHE (decryptable only by donor via CoFHE)
• No Zcash transaction IDs stored (shielded txns remain private)
• Public mappings track funded status: fundedBuilders[ipfsHash], totalFundingAmount[ipfsHash]

Functions:

• mintImpact(...): Mint SBT with encrypted amount
• isBuilderFunded(string ipfsHash): Check if builder has been funded
• getTotalFundingAmount(string ipfsHash): Get total funding (in zatoshis)

NetworkSchoolVerifier (Fhenix)

FHE-based verification proving Network School residency without revealing cohort.

Verification Flow:

1. Builder signs message: keccak256(contract, chainId, claimant, member, nonce)
2. Contract verifies signature from allowlisted member address
3. Stores encrypted verification flag: verifiedEnc[claimant] = FHE.asEbool(true)
4. Only claimant can decrypt via CoFHE coprocessor

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Getting Started

Prerequisites

• Node.js 18+ (or Bun)
• An EVM wallet (MetaMask, Rabby, Talisman, etc.) with Sepolia ETH
• Zcash wallet (for receiving donations, optional for testing)

Installation

# Clone the repository
git clone https://github.com/your-org/privora.git
cd privora

# Install dependencies
npm install
# or
bun install

# Set up environment variables
cp .env.example .env

Environment Variables

# NEAR AI (for PII stripping and matching)
NEXT_PUBLIC_NEAR=your_near_ai_api_key

# Reclaim Protocol (for ZK proofs)
NEXT_PUBLIC_RECLAIM_APP_ID=your_app_id
NEXT_PUBLIC_RECLAIM_APP_SECRET=your_app_secret

# Smart Contracts (Sepolia)
NEXT_PUBLIC_INDEX_CONTRACT=0x...  # PersonaRegistry address
NEXT_PUBLIC_IMPACT_SBT_CONTRACT=0x...  # ImpactSBT address
NEXT_PUBLIC_NETWORK_SCHOOL_VERIFIER=0x...  # NetworkSchoolVerifier address
NEXT_PUBLIC_RPC_URL=https://eth-sepolia.g.alchemy.com/v2/your_key

# Thirdweb
NEXT_PUBLIC_TEMPLATE_CLIENT_ID=your_thirdweb_client_id

Development

# Start development server
npm run dev
# or
bun dev

# Open http://localhost:3000

Deploying Contracts

cd cofhe-hardhat-starter

# Compile contracts
npx hardhat compile

# Deploy to Sepolia
npx hardhat deploy-impact-sbt --network sepolia
npx hardhat deploy-network-school --network sepolia

# Update .env with deployed addresses

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Usage

For Builders (Recipients)

1. Create Profile: Navigate to /recipient and fill out pseudonymous profile

   • Choose a pseudonym (no real names)
   • Select category and skills
   • Write bio (will be PII-stripped by NEAR AI)
   • Add funding need description

2. Attach ZK Proofs: Verify credibility without revealing identity

   • GitHub contributions (via Reclaim)
   • Leetcode activity (via Reclaim)
   • Scholar profile (via Reclaim)
   • Location verification (via Reclaim)
   • Network School residency (via FHE contract)

3. Add Payment Address: Provide Zcash shielded address (zs1...)

4. Publish: Profile is uploaded to IPFS and indexed on-chain

For Patrons (Donors)

1. Set Intent: Navigate to /donor and specify preferences

   • Topics of interest
   • Geographic focus
   • Funding amount
   • Free-form intent text (optional)

2. Find Matches: AI matches your intent against available builders

   • NEAR AI analyzes profiles and returns ranked matches
   • View match scores, reasons, and verification badges

3. Fund Directly: Browse all builders or fund matched recipients

   • Scan QR code with Zcash wallet
   • Send shielded transaction
   • Mint Impact SBT (proves your donation without revealing amount)

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Privacy Guarantees

What's Private

• Payment amounts: Encrypted in Zcash shielded transactions
• Donor identity: No on-chain link between EVM address and Zcash address
• Recipient identity: Pseudonyms only, no real names or locations
• Transaction graph: No public ledger showing who funded whom

What's Public

• IPFS profile hashes: Content-addressed references (profiles themselves are encrypted)
• Verification flags: Boolean indicators (e.g., "has GitHub proof") without revealing details
• Funding status: Whether a builder has been funded (not amounts or donors)
• Impact SBT metadata: Donor address, builder pseudonym, cause tag (amounts encrypted)

Threat Model

Privora is designed for scenarios where:

• Donors need to remain anonymous (political repression, surveillance states)
• Recipients need pseudonymity (activists, dissidents, high-risk builders)
• Funding amounts should be private (prevent targeting based on wealth)

Not designed for:

• Regulatory compliance (no KYC/AML)
• Tax reporting (amounts are private)
• Public accountability (by design, transactions are private)

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Contributing

Privora is built for high-risk philanthropy. Contributions should maintain the privacy-first architecture.

Areas for Contribution

• Additional ZK proof systems: Integrate Semaphore, Sismo, or other proof protocols
• More startup societies: Add verification for YC, Antler, The Residency
• UI/UX improvements: Better empty states, loading skeletons, mobile optimization
• Documentation: Technical deep-dives, threat model analysis, deployment guides

Development Guidelines

• Privacy by default: Never add features that leak identity or amounts
• Minimal on-chain data: Store only what's necessary for coordination
• Cryptographic guarantees: Prefer ZK proofs over trusted intermediaries
• Separation of concerns: Keep payment, coordination, and identity layers separate

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License

MIT License - See LICENSE for details.

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Acknowledgments

Built with:

• Zcash for shielded transactions
• NEAR Protocol for coordination layer
• Fhenix CoFHE for FHE-enabled contracts
• Reclaim Protocol for ZK proofs
• NEAR AI for PII stripping and matching

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Privacy is not a feature—it's a requirement for high-risk philanthropy.