Shadow Match's security model is built on three pillars:

1. Arcium's encrypted compute platform
2. Solana's account model security
3. Protocol-level privacy guarantees

• Order price
• Order quantity
• Trading intention (before match)
• Trader identity (optional)

// Encrypted order data structure
#[derive(ArcisType, Copy, Clone, ArcisEncryptable)]
pub struct Order {
    pub id: mu64,           // Order ID
    pub trader: mu128,      // Encrypted trader ID
    pub is_buy: mbool,      // Encrypted order side
    pub price: mu64,        // Encrypted price
    pub quantity: mu64,     // Encrypted quantity
    pub timestamp: mu64,    // Submission time
}

Orders are committed on-chain using a privacy-preserving commitment scheme:

1. Hash-based commitment:

   commitment = SHA256(
       orderID || 
       traderPubkey || 
       side || 
       price || 
       quantity || 
       nonce
   )

2. Properties:

   • Binding: Cannot change order after commitment
   • Hiding: Cannot derive order details from commitment
   • Unique: Each order has distinct commitment

1. Circuit-level privacy:

   • Matching occurs in Arcium's encrypted environment
   • Only match results are revealed
   • Price discovery remains confidential

2. Settlement privacy:

   • Token transfers reveal final execution price
   • Partial fill amounts stay private
   • Trading history is pseudonymous

• Front-running attacks
• Order manipulation
• Privacy leaks
• Settlement attacks
• Relayer misbehavior

• Solana network attacks
• Arcium platform compromises
• Hardware-level attacks
• Social engineering

1. Order Integrity

   • Orders cannot be forged
   • Commitments cannot be altered
   • Matches must be valid

2. Economic Security

   • No free option attacks
   • Price/time priority preserved
   • Fair match execution

3. Privacy Guarantees

   • Order details stay encrypted
   • Minimal information leakage
   • Optional trader anonymity

1. Front-running

   • Vector: MEV bots observing pending orders
   • Mitigation: Encrypted order details + commitments

2. Order Manipulation

   • Vector: Relayer reordering matches
   • Mitigation: Provable fair matching in circuit

3. Privacy Leaks

   • Vector: Transaction graph analysis
   • Mitigation: Optional mixer integration

// PDA derivation with proper seeds
[account(
    seeds = [b"order", commitment_hash.as_ref()],
    bump,
    payer = user,
    space = OrderAccount::SIZE
)]
pub order_account: Account<'info, OrderAccount>;

// Proper authority checks
#[account(
    mut,
    constraint = user_account.owner == user.key()
)]
pub user_account: Account<'info, UserAccount>;

// Safe math operations
let new_balance = user_account.balance
    .checked_add(amount)
    .ok_or(ErrorCode::Overflow)?;

// Secure matching logic
#[instruction]
pub fn match_orders(
    new_order: Enc<Shared, Order>,
    book_orders: Enc<Mxe, &[Order]>,
) -> Enc<Mxe, MatchResult> {
    // Constant-time matching
    // No control flow leaks
    // Secure comparisons
}

// Rate limiting
const rateLimiter = new RateLimiter({
    windowMs: 15 * 60 * 1000,
    max: 100
});

// Request validation
function validateOrder(order: EncryptedOrder) {
    if (!order.signature || !verifySignature(order)) {
        throw new Error("Invalid order signature");
    }
}

// Secure WebSocket handling
wss.on('connection', (ws) => {
    ws.on('message', async (msg) => {
        try {
            // Validate message
            // Process safely
            // Handle errors
        } catch (e) {
            ws.close();
        }
    });
});

• All PRs require 2 approvals
• Security-critical changes need audit
• Automated security scanning
• Regular dependency audits

// Property-based testing
describe("Security Properties", () => {
    it("maintains privacy", async () => {
        // Generate random orders
        // Verify no information leakage
        // Check commitment properties
    });
});

// Invariant testing
describe("Security Invariants", () => {
    it("preserves balances", async () => {
        // Track all balances
        // Execute random trades
        // Verify conservation
    });
});

• Circuit execution monitoring
• Unusual order patterns
• Settlement failures
• Balance discrepancies

1. Circuit compromise:

   • Pause matching
   • Investigate breach
   • Generate new circuits

2. Contract vulnerability:

   • Trigger circuit breaker
   • Pause operations
   • Deploy fixes

1. Assessment phase:

   • Identify scope
   • Evaluate impact
   • Plan mitigation

2. Resolution phase:

   • Deploy fixes
   • Verify security
   • Resume operations

• Security alerts channel
• Status page updates
• Post-mortem reports

• Dependency updates
• Error monitoring
• Performance analysis

• Circuit audits
• Contract reviews
• Integration tests

• Full security audit
• Penetration testing
• Process review