Sukura

Sukura is a privacy-preserving transaction mixer built on Solana. It enables users to deposit and withdraw funds anonymously by leveraging zk-proofs.

🔥 Features

• Privacy-Preserving Transactions – Uses ZKPs to ensure transactions remain confidential.
• Solana Smart Contracts – Efficient, low-cost on-chain interactions.
• Relayer Support – Withdraw funds without linking addresses.
• Web3 Integration – Works with wallets like Phantom and Solflare.
• Fast & Scalable – Built on Solana for high-speed transactions.

🛠 Tech Stack

• Solana – Blockchain infrastructure
• Anchor – Solana smart contract framework
• Next.js – Frontend & API routes
• MongoDB – Stores Merkle tree data off-chain
• Mongoose – ODM for MongoDB
• Shyft API – Transaction relayer
• Circom – Used for writing ZK circuit.

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🚀 Getting Started

1️⃣ Clone the Repository

 git clone https://github.com/truthixify/sukura.git
 cd sukura

2️⃣ Install Dependencies

npm install

3️⃣ Set Up Environment Variables

Create a .env.local file and configure it:

MONGODB_URI=<your_mongodb_connection_string>
API_KEY=<your_shyft_api_key>
NETWORK_URL=<solana_rpc_url>
NETWORK_URL=devnet # or mainnet
NODE_ENV=development # or production

4️⃣ Run the Development Server

npm run dev

Your Next.js app should now be running at http://localhost:3000

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📜 How it Works

1️⃣ Deposit Process

1. User Generates a Commitment
   • During deposit, a random secret is generated.
   • The Poseidon hash function is used to create a commitment hash.
2. Commitment is Stored On-Chain
   • The commitment is submitted to the Solana smart contract.
   • The commitment is also stored off-chain in a Merkle tree (MongoDB).
3. User Downloads a Note
   • After a successful deposit, the user downloads a “Note”.
   • The note contains the secret key and nullifier needed for withdrawal.

Deposit Parameters:

{
    commitment: string // Unique commitment hash
}

2️⃣ Withdrawal Process

1. User Uploads Their Note
   • To withdraw, the user must upload the Note downloaded during deposit.
   • This note contains the secret key used to prove ownership.
2. Zero-Knowledge Proof is Generated
   • A ZK proof is created to verify the deposit without revealing its details.
   • The proof is submitted to the smart contract along with the Merkle root.
3. Relayer Facilitates the Transaction
   • A relayer submits the withdrawal transaction on behalf of the user.
   • The withdrawal amount is sent to the recipient address without linking it to the original deposit.

Withdrawal Parameters:

{
    nullifierHash: string // Prevents double spending
    root: string // Current Merkle tree root
    proof: Proof // Zero-knowledge proof
    publicSignals: PublicSignals // Public inputs for verification
    fee: BN // Transaction fee
    recipientAddress: PublicKey // Address receiving the funds
    relayerWallet: PublicKey // Relayer handling the transaction
    vaultAddress: PublicKey // Vault holding the funds
}

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🏗 Contributing

1. Fork the repo
2. Create a new branch (git checkout -b feature/new-feature)
3. Commit your changes (git commit -m 'Add new feature')
4. Push the branch (git push origin feature/new-feature)
5. Open a pull request

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📜 License

MIT License © 2025 Sukura Team

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📬 Contact

• Twitter: @truthixify
• Email: [email protected]