Confidex Technical Documentation

Confidex is a confidential decentralized exchange implementing a two-layer privacy architecture using Arcium MPC for encrypted order matching and ShadowWire for private settlement. All order data (price, quantity, side, trader identity) is encrypted on-chain and only decrypted within the MPC cluster for matching.

Two-Layer Privacy Architecture

Confidex uses Arcium MPC as the primary privacy layer - all order data (price, quantity, side, trader identity) is encrypted on-chain. ShadowWire provides private settlement with hidden transfer amounts. ZK eligibility proofs are available as an optional compliance layer for regulated use cases.

ZK Compliance Layer

The eligibility circuit proves blacklist non-membership without revealing the user's address. This enables regulatory compliance (KYC/AML screening) while preserving user privacy.

// circuits/eligibility/src/main.nr
fn main(
    // Public input - stored on-chain
    blacklist_root: pub Field,

    // Private inputs - never revealed
    merkle_path: [Field; 20],
    path_indices: [Field; 20]
) {
    // Verify SMT non-membership by checking path leads to empty leaf
    // The address is derived from path_indices, never passed directly
    let valid = verify_smt_non_membership(
        blacklist_root,
        merkle_path,
        path_indices
    );

    assert(valid, "Address is blacklisted or proof invalid");
    // Proof passes = address NOT on blacklist
}

MPC Execution Layer

Arcium's Multi-Party Computation enables encrypted order matching. Prices and amounts are encrypted before submission - the MPC cluster compares them without ever decrypting, preventing front-running and MEV extraction.

Settlement Layer

Settlement executes the final token transfers after MPC matching completes. We support multiple settlement providers with automatic fallback for maximum reliability.

// 64-byte V2 pure ciphertext format
[nonce (16 bytes) | ciphertext (32 bytes) | ephemeral_pk (16 bytes)]

Bytes 0-15:  Nonce             → MPC decryption seed
Bytes 16-47: Ciphertext        → Fully encrypted value
Bytes 48-63: Ephemeral pubkey  → MPC key routing

// No plaintext prefix - complete privacy

Complete Data Flow

From order placement to settlement, here's how data flows through the three privacy layers:

Security Model & Privacy Guarantees

Production Readiness

Confidex is production-ready for hackathon demo with real token movements, persistent settlement tracking, and live order book data from the chain.

# Enable crank service
CRANK_ENABLED=true

# Production MPC (default is TRUE as of Jan 2026)
CRANK_USE_REAL_MPC=true

# Configuration
CRANK_POLLING_INTERVAL_MS=5000    # Check for matches every 5s
CRANK_USE_ASYNC_MPC=true          # Production async MPC flow
CRANK_MAX_CONCURRENT_MATCHES=5    # Parallel match attempts
CRANK_DB_PATH=./data/crank.db        # SQLite persistence

# Check crank status
curl http://localhost:3001/admin/crank/status

Program IDs & Accounts

Frequently Asked Questions

Common questions about wallet warnings, privacy features, and trading on Confidex.

Future Implementations

Confidex is continuously improving privacy coverage. These are planned enhancements that will further strengthen the privacy guarantees of the protocol.