Privacy Cash Rust SDK

Pure Rust SDK for Privacy Cash - Privacy-preserving transactions on Solana using Zero-Knowledge Proofs.

iOS Compatible - No Node.js required!

Features

Private Transactions - Send SOL and SPL tokens with complete privacy
Pure Rust ZK Proofs - Native Groth16 proof generation
iOS Compatible - Use as a Rust crate in mobile apps
Multi-Token Support - SOL, USDC, USDT
One Function API - send_privately() does everything

Installation

Add to your Cargo.toml:

[dependencies]
privacy-cash = { git = "https://github.com/Nova-Shield/privacy-cash-rust-sdk" }
tokio = { version = "1", features = ["full"] }

Circuit Files (Required)

Download the circuit files (~60MB total):

mkdir -p circuit
curl -L -o circuit/transaction2.wasm "https://privacy.cash/circuits/transaction2.wasm"
curl -L -o circuit/transaction2.zkey "https://privacy.cash/circuits/transaction2.zkey"

Quick Start - ONE Function!

use privacy_cash::send_privately;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Send 0.1 SOL privately - ONE function does everything!
    let result = send_privately(
        "your_base58_private_key",  // Private key
        "recipient_pubkey",          // Recipient address
        0.1,                         // Amount to send
        "sol",                       // Token: "sol", "usdc", "usdt"
        None,                        // Optional RPC URL
    ).await?;
    
    println!("Sent privately!");
    println!("Deposit TX: {}", result.deposit_signature);
    println!("Withdraw TX: {}", result.withdraw_signature);
    println!("Recipient received: {} lamports", result.amount_received);
    
    Ok(())
}

The send_privately() function automatically:

Deposits your tokens into Privacy Cash
Waits for blockchain confirmation
Withdraws the maximum amount to the recipient

API

SendPrivatelyResult

pub struct SendPrivatelyResult {
    pub deposit_signature: String,   // Deposit transaction
    pub withdraw_signature: String,  // Withdraw transaction
    pub amount_deposited: u64,       // Amount deposited
    pub amount_received: u64,        // Amount recipient received
    pub total_fees: u64,             // Total fees paid
    pub recipient: String,           // Recipient address
    pub token: String,               // Token type
}

Supported Tokens

Token	Minimum	Fee
SOL	0.02 SOL	~0.006 SOL
USDC	2 USDC	~0.85 USDC
USDT	2 USDT	~0.85 USDT

Examples

# Check balances
SOLANA_PRIVATE_KEY="your-key" cargo run --release --example check_balance

# Send 0.02 SOL privately
SOLANA_PRIVATE_KEY="your-key" cargo run --release --example send_privately -- 0.02 sol

# Send 10 USDC privately to a recipient
SOLANA_PRIVATE_KEY="your-key" cargo run --release --example send_privately -- 10 usdc RecipientPubkey

Security

Never hardcode private keys in your code
Use environment variables or secure key management
Private keys are used locally and never sent to any server
All ZK proofs are generated client-side

privacy-cash 0.2.0