# QuDAG Network Implementation Plan
## Overview
This document provides detailed implementation guidance for the QuDAG networking layer, with specific code examples and integration patterns for each component.
## 1. Enhanced libp2p Transport Implementation
### 1.1 Quantum-Secure Transport Wrapper
```rust
// File: src/transport/quantum_secure.rs
use libp2p::{Transport, core::upgrade};
use crate::quantum_crypto::{MLKEMKeyPair, SharedSecret};
pub struct QuantumSecureTransport<T> {
inner_transport: T,
ml_kem_keypair: MLKEMKeyPair,
security_level: MLKEMSecurityLevel,
}
impl<T> QuantumSecureTransport<T>
where
T: Transport,
{
pub fn new(transport: T, security_level: MLKEMSecurityLevel) -> Self {
Self {
inner_transport: transport,
ml_kem_keypair: MLKEMKeyPair::generate(security_level),
security_level,
}
}
// Upgrade connection with post-quantum handshake
async fn quantum_handshake<C>(&self, conn: C) -> Result<QuantumConnection<C>>
where
C: AsyncRead + AsyncWrite + Unpin,
{
// 1. Send our ML-KEM public key
let our_public_key = self.ml_kem_keypair.public_key();
conn.write_all(&our_public_key.to_bytes()).await?;
// 2. Receive peer's ML-KEM public key
let mut peer_public_key_bytes = vec![0u8; ML_KEM_PUBLIC_KEY_SIZE];
conn.read_exact(&mut peer_public_key_bytes).await?;
let peer_public_key = MLKEMPublicKey::from_bytes(&peer_public_key_bytes)?;
// 3. Generate shared secret
let (ciphertext, shared_secret) = peer_public_key.encapsulate()?;
conn.write_all(&ciphertext.to_bytes()).await?;
// 4. Derive session keys
let session_keys = self.derive_session_keys(&shared_secret);
Ok(QuantumConnection {
inner: conn,
encryption_key: session_keys.encryption,
decryption_key: session_keys.decryption,
nonce_counter: AtomicU64::new(0),
})
}
}
```
### 1.2 QUIC Transport with ML-KEM
```rust
// File: src/transport/quic.rs
use quinn::{Endpoint, ClientConfig, ServerConfig};
use rustls::{Certificate, PrivateKey};
pub struct QuicTransport {
endpoint: Endpoint,
ml_kem_integration: MLKEMIntegration,
}
impl QuicTransport {
pub async fn new(config: QuicConfig) -> Result<Self> {
// Configure QUIC with custom crypto
let mut transport_config = quinn::TransportConfig::default();
transport_config
.max_concurrent_bidi_streams(256u16.into())
.max_concurrent_uni_streams(256u16.into())
.max_idle_timeout(Some(Duration::from_secs(300).try_into()?))
.keep_alive_interval(Some(Duration::from_secs(30)));
// Create TLS config with post-quantum crypto
let tls_config = Self::create_quantum_tls_config()?;
// Build endpoint
let server_config = ServerConfig::with_crypto(Arc::new(tls_config));
let endpoint = Endpoint::server(server_config, config.listen_addr)?;
Ok(Self {
endpoint,
ml_kem_integration: MLKEMIntegration::new(config.security_level),
})
}
fn create_quantum_tls_config() -> Result<rustls::ServerConfig> {
// Custom TLS configuration with ML-KEM integration
let config = rustls::ServerConfig::builder()
.with_safe_defaults()
.with_custom_certificate_verifier(Arc::new(QuantumCertVerifier::new()))
.with_single_cert(cert_chain, key)?;
Ok(config)
}
}
```
## 2. Kademlia DHT Implementation
### 2.1 Enhanced Kademlia with Dark Addressing
```rust
// File: src/discovery/kademlia.rs
use libp2p::kad::{Kademlia, KademliaConfig, store::MemoryStore, Record};
use libp2p::PeerId;
pub struct EnhancedKademlia {
kademlia: Kademlia<MemoryStore>,
dark_resolver: Arc<DarkResolver>,
reputation_manager: Arc<ReputationManager>,
}
impl EnhancedKademlia {
pub fn new(peer_id: PeerId, config: EnhancedKademliaConfig) -> Self {
let store = MemoryStore::new(peer_id);
let mut kad_config = KademliaConfig::default();
kad_config.set_replication_factor(NonZeroUsize::new(20).unwrap());
kad_config.set_query_timeout(Duration::from_secs(60));
kad_config.set_record_ttl(Some(Duration::from_secs(86400))); // 24 hours
let kademlia = Kademlia::with_config(peer_id, store, kad_config);
Self {
kademlia,
dark_resolver: Arc::new(DarkResolver::new()),
reputation_manager: Arc::new(ReputationManager::new()),
}
}
// Store dark address mapping
pub async fn store_dark_address(&mut self, dark_addr: DarkAddress, endpoint: NetworkEndpoint) -> Result<()> {
// Create DHT record
let key = self.dark_address_to_key(&dark_addr);
let value = self.encrypt_endpoint(&endpoint)?;
let record = Record {
key,
value,
publisher: None,
expires: Some(Instant::now() + Duration::from_secs(86400)),
};
self.kademlia.put_record(record, Quorum::One)?;
Ok(())
}
// Resolve dark address
pub async fn resolve_dark_address(&mut self, dark_addr: &DarkAddress) -> Result<NetworkEndpoint> {
let key = self.dark_address_to_key(dark_addr);
match self.kademlia.get_record(&key) {
Ok(record) => {
let endpoint = self.decrypt_endpoint(&record.value)?;
Ok(endpoint)
}
Err(_) => Err(NetworkError::DarkAddressNotFound),
}
}
// Reputation-weighted peer discovery
pub async fn find_peers_weighted(&mut self, key: &[u8], count: usize) -> Vec<PeerId> {
let raw_peers = self.kademlia.get_closest_peers(key);
// Sort by reputation
let mut scored_peers: Vec<(PeerId, f64)> = raw_peers
.into_iter()
.map(|peer| {
let reputation = self.reputation_manager.get_reputation(&peer);
(peer, reputation)
})
.collect();
scored_peers.sort_by(|a, b| b.1.partial_cmp(&a.1).unwrap());
scored_peers
.into_iter()
.take(count)
.map(|(peer, _)| peer)
.collect()
}
}
```
### 2.2 Bootstrap Process
```rust
// File: src/discovery/bootstrap.rs
pub struct BootstrapManager {
bootstrap_peers: Vec<Multiaddr>,
kad: Arc<Mutex<EnhancedKademlia>>,
connection_manager: Arc<ConnectionManager>,
}
impl BootstrapManager {
pub async fn bootstrap(&self) -> Result<()> {
info!("Starting bootstrap process");
// Phase 1: Connect to bootstrap nodes
let mut successful_connections = 0;
for addr in &self.bootstrap_peers {
match self.connection_manager.connect_to_address(addr).await {
Ok(peer_id) => {
info!("Connected to bootstrap peer: {}", peer_id);
self.kad.lock().await.add_address(&peer_id, addr.clone());
successful_connections += 1;
}
Err(e) => {
warn!("Failed to connect to bootstrap peer {}: {}", addr, e);
}
}
}
if successful_connections == 0 {
return Err(NetworkError::BootstrapFailed);
}
// Phase 2: Random walk to populate routing table
let random_peer_id = PeerId::random();
self.kad.lock().await.get_closest_peers(random_peer_id);
// Phase 3: Announce our presence
let our_info = self.create_peer_info();
self.kad.lock().await.put_record(our_info).await?;
Ok(())
}
}
```
## 3. Onion Routing Implementation
### 3.1 Circuit Construction
```rust
// File: src/onion/circuit.rs
pub struct CircuitBuilder {
peer_selector: Arc<PeerSelector>,
ml_kem: Arc<QuantumKeyExchange>,
max_circuit_length: usize,
}
impl CircuitBuilder {
pub async fn build_circuit(&self, destination: &PeerId, hops: usize) -> Result<Circuit> {
// Select relay nodes
let relays = self.select_relay_nodes(hops).await?;
let mut circuit_hops = Vec::new();
let mut layer_keys = Vec::new();
// Build circuit hop by hop
for (i, relay) in relays.iter().enumerate() {
// Establish encrypted channel with relay
let (shared_secret, hop_info) = self.establish_hop(relay, i == 0).await?;
circuit_hops.push(hop_info);
layer_keys.push(shared_secret);
}
// Add destination as final hop
let dest_hop = self.create_destination_hop(destination).await?;
circuit_hops.push(dest_hop);
Ok(Circuit {
id: CircuitId::generate(),
hops: circuit_hops,
layer_keys,
created_at: Instant::now(),
state: CircuitState::Active,
})
}
async fn establish_hop(&self, relay: &RelayNode, is_entry: bool) -> Result<(SharedSecret, CircuitHop)> {
// ML-KEM key exchange with relay
let (ciphertext, shared_secret) = relay.public_key.encapsulate()?;
// Send CREATE cell
let create_cell = CreateCell {
circuit_id: CircuitId::generate(),
kem_ciphertext: ciphertext,
handshake_data: self.create_handshake_data(is_entry),
};
let response = relay.send_create_cell(create_cell).await?;
// Verify response and extract hop info
let hop_info = CircuitHop {
peer_id: relay.peer_id,
shared_secret: shared_secret.clone(),
next_hop_encrypted: None,
};
Ok((shared_secret, hop_info))
}
}
```
### 3.2 Message Encryption and Routing
```rust
// File: src/onion/routing.rs
pub struct OnionRouter {
circuits: Arc<DashMap<CircuitId, Circuit>>,
cell_crypto: CellCrypto,
mixer: TrafficMixer,
}
impl OnionRouter {
pub async fn send_message(&self, message: &[u8], circuit_id: CircuitId) -> Result<()> {
let circuit = self.circuits.get(&circuit_id)
.ok_or(OnionError::CircuitNotFound)?;
// Fragment into fixed-size cells
let cells = self.fragment_message(message);
// Apply onion encryption
let encrypted_cells = self.encrypt_cells(cells, &circuit)?;
// Add to mixing pool
for cell in encrypted_cells {
self.mixer.add_cell(cell).await;
}
Ok(())
}
fn encrypt_cells(&self, cells: Vec<Cell>, circuit: &Circuit) -> Result<Vec<EncryptedCell>> {
let mut encrypted_cells = Vec::new();
for cell in cells {
let mut encrypted_payload = cell.payload;
// Apply encryption layers in reverse order
for (i, key) in circuit.layer_keys.iter().enumerate().rev() {
encrypted_payload = self.cell_crypto.encrypt_layer(
&encrypted_payload,
key,
circuit.hops[i].peer_id,
)?;
}
encrypted_cells.push(EncryptedCell {
circuit_id: circuit.id,
encrypted_payload,
cell_type: cell.cell_type,
});
}
Ok(encrypted_cells)
}
}
// Traffic mixing for timing analysis resistance
pub struct TrafficMixer {
cell_queue: Arc<Mutex<VecDeque<MixedCell>>>,
mix_delay: Duration,
batch_size: usize,
}
impl TrafficMixer {
pub async fn add_cell(&self, cell: EncryptedCell) {
let mixed_cell = MixedCell {
cell,
added_at: Instant::now(),
send_at: Instant::now() + self.random_delay(),
};
self.cell_queue.lock().await.push_back(mixed_cell);
}
pub async fn mix_and_send_loop(&self) {
loop {
sleep(self.mix_delay).await;
let cells_to_send = self.get_cells_to_send().await;
if cells_to_send.len() >= self.batch_size {
self.send_batch(cells_to_send).await;
}
}
}
}
```
## 4. Dark Addressing Implementation
### 4.1 Address Generation and Management
```rust
// File: src/dark_addressing/generator.rs
pub struct DarkAddressManager {
identity_keys: MLDSAKeyPair,
address_cache: Arc<DashMap<DarkAddress, AddressMetadata>>,
resolver: Arc<DarkResolver>,
}
impl DarkAddressManager {
pub fn generate_address(&self, network_type: NetworkType) -> DarkAddress {
// Generate ephemeral identity
let ephemeral_key = MLDSAKeyPair::generate();
// Create address components
let components = AddressComponents {
version: DARK_ADDRESS_VERSION,
network_type,
identity_commitment: self.create_identity_commitment(&ephemeral_key),
timestamp: SystemTime::now(),
};
// Encode address
let address = self.encode_address(components);
// Store metadata
let metadata = AddressMetadata {
ephemeral_key,
created_at: Instant::now(),
last_used: None,
resolution_count: 0,
};
self.address_cache.insert(address.clone(), metadata);
address
}
fn create_identity_commitment(&self, ephemeral_key: &MLDSAKeyPair) -> [u8; 32] {
let mut hasher = Blake3::new();
hasher.update(&ephemeral_key.public_key().to_bytes());
hasher.update(&self.identity_keys.public_key().to_bytes());
hasher.update(&SystemTime::now().duration_since(UNIX_EPOCH).unwrap().as_secs().to_le_bytes());
let hash = hasher.finalize();
let mut commitment = [0u8; 32];
commitment.copy_from_slice(hash.as_bytes());
commitment
}
pub async fn publish_address(&self, address: &DarkAddress, endpoint: &NetworkEndpoint) -> Result<()> {
// Create resolution proof
let proof = self.create_resolution_proof(address, endpoint)?;
// Encrypt endpoint information
let encrypted_endpoint = self.encrypt_endpoint(endpoint, address)?;
// Create DHT record
let record = DarkAddressRecord {
address: address.clone(),
encrypted_endpoint,
proof,
expires_at: SystemTime::now() + Duration::from_secs(86400),
};
// Publish to DHT
self.resolver.publish_record(record).await
}
}
```
### 4.2 Resolution Protocol
```rust
// File: src/dark_addressing/resolver.rs
pub struct DarkResolver {
dht: Arc<EnhancedKademlia>,
cache: Arc<TimedCache<DarkAddress, ResolvedEndpoint>>,
privacy_config: PrivacyConfig,
}
impl DarkResolver {
pub async fn resolve(&self, address: &DarkAddress) -> Result<ResolvedEndpoint> {
// Check cache first
if let Some(cached) = self.cache.get(address).await {
return Ok(cached);
}
// Add privacy measures
if self.privacy_config.enable_dummy_queries {
self.send_dummy_queries().await;
}
// Add random delay
let delay = self.privacy_config.random_delay();
sleep(delay).await;
// Query DHT
let record = self.query_dht(address).await?;
// Verify proof
self.verify_resolution_proof(&record)?;
// Decrypt endpoint
let endpoint = self.decrypt_endpoint(&record.encrypted_endpoint, address)?;
// Cache result
self.cache.insert(address.clone(), endpoint.clone()).await;
Ok(endpoint)
}
async fn send_dummy_queries(&self) {
let num_dummies = thread_rng().gen_range(2..5);
for _ in 0..num_dummies {
let dummy_address = DarkAddress::random();
// Fire and forget dummy query
let dht = self.dht.clone();
tokio::spawn(async move {
let _ = dht.query(&dummy_address.to_key()).await;
});
}
}
}
```
## 5. NAT Traversal Implementation
### 5.1 Multi-Strategy NAT Traversal
```rust
// File: src/nat/traversal.rs
pub struct NATTraversal {
strategies: Vec<Box<dyn NATStrategy>>,
stun_client: StunClient,
upnp_client: Option<UpnpClient>,
relay_manager: RelayManager,
}
impl NATTraversal {
pub async fn establish_connection(&self, peer: &PeerId) -> Result<NATConnection> {
// Try strategies in order of preference
// 1. Try direct connection first
if let Ok(conn) = self.try_direct_connection(peer).await {
return Ok(conn);
}
// 2. STUN for address discovery
let external_addr = self.stun_client.get_external_address().await?;
// 3. Try UPnP if available
if let Some(upnp) = &self.upnp_client {
if let Ok(mapping) = upnp.create_port_mapping(external_addr.port()).await {
if let Ok(conn) = self.try_mapped_connection(peer, mapping).await {
return Ok(conn);
}
}
}
// 4. Hole punching
if let Ok(conn) = self.try_hole_punching(peer, external_addr).await {
return Ok(conn);
}
// 5. Fallback to relay
self.establish_relayed_connection(peer).await
}
async fn try_hole_punching(&self, peer: &PeerId, our_addr: SocketAddr) -> Result<NATConnection> {
// Coordinate via signaling server
let peer_addr = self.exchange_addresses(peer, our_addr).await?;
// Simultaneous open
let socket = UdpSocket::bind(our_addr).await?;
// Send packets to create NAT mapping
for _ in 0..5 {
socket.send_to(b"PUNCH", peer_addr).await?;
sleep(Duration::from_millis(100)).await;
}
// Try to receive from peer
let mut buf = [0u8; 1024];
match timeout(Duration::from_secs(5), socket.recv_from(&mut buf)).await {
Ok(Ok((len, addr))) if addr == peer_addr => {
// Success! Upgrade to full connection
self.upgrade_punched_connection(socket, peer_addr).await
}
_ => Err(NetworkError::HolePunchingFailed),
}
}
}
```
### 5.2 Relay Protocol
```rust
// File: src/nat/relay.rs
pub struct RelayManager {
relay_nodes: Vec<RelayNode>,
active_circuits: Arc<DashMap<PeerId, RelayCircuit>>,
}
impl RelayManager {
pub async fn establish_relayed_connection(&self, target: &PeerId) -> Result<RelayedConnection> {
// Select best relay based on latency and load
let relay = self.select_optimal_relay(target).await?;
// Establish circuit through relay
let circuit = relay.create_circuit(target).await?;
// Store active circuit
self.active_circuits.insert(*target, circuit.clone());
Ok(RelayedConnection {
circuit,
relay_node: relay,
bandwidth_limit: self.calculate_bandwidth_limit(&relay),
})
}
async fn select_optimal_relay(&self, target: &PeerId) -> Result<RelayNode> {
let mut candidates = Vec::new();
// Evaluate each relay
for relay in &self.relay_nodes {
let score = self.evaluate_relay(relay, target).await?;
candidates.push((relay.clone(), score));
}
// Sort by score
candidates.sort_by(|a, b| b.1.partial_cmp(&a.1).unwrap());
candidates
.into_iter()
.next()
.map(|(relay, _)| relay)
.ok_or(NetworkError::NoRelayAvailable)
}
}
```
## 6. Testing Strategy
### 6.1 Integration Test Setup
```rust
// File: tests/network_integration.rs
#[tokio::test]
async fn test_full_network_stack() {
// Create test network
let mut network = TestNetwork::new(10).await;
// Bootstrap nodes
network.bootstrap_all().await;
// Test Kademlia DHT
let test_key = b"test_key";
let test_value = b"test_value";
let node1 = &network.nodes[0];
node1.kad.put_record(test_key, test_value).await.unwrap();
let node2 = &network.nodes[5];
let result = node2.kad.get_record(test_key).await.unwrap();
assert_eq!(result, test_value);
// Test onion routing
let circuit = node1.build_circuit(&node2.peer_id(), 3).await.unwrap();
node1.send_onion_message(b"secret message", circuit).await.unwrap();
// Test dark addressing
let dark_addr = node1.generate_dark_address().await;
node1.publish_dark_address(&dark_addr).await.unwrap();
let resolved = node2.resolve_dark_address(&dark_addr).await.unwrap();
assert_eq!(resolved.peer_id, node1.peer_id());
}
```
### 6.2 Performance Benchmarks
```rust
// File: benches/network_performance.rs
#[bench]
fn bench_ml_kem_handshake(b: &mut Bencher) {
let runtime = Runtime::new().unwrap();
b.iter(|| {
runtime.block_on(async {
let transport = QuantumSecureTransport::new();
let conn = create_test_connection();
transport.quantum_handshake(conn).await.unwrap()
})
});
}
#[bench]
fn bench_onion_encryption(b: &mut Bencher) {
let router = OnionRouter::new();
let circuit = create_test_circuit(5); // 5 hops
let message = vec![0u8; 1024]; // 1KB message
b.iter(|| {
router.encrypt_message(&message, &circuit).unwrap()
});
}
#[bench]
fn bench_dht_lookup(b: &mut Bencher) {
let runtime = Runtime::new().unwrap();
let mut kad = create_test_kad();
populate_kad(&mut kad, 1000); // 1000 nodes
b.iter(|| {
runtime.block_on(async {
let key = random_key();
kad.get_record(&key).await
})
});
}
```
## 7. Monitoring and Metrics
### 7.1 Network Metrics Collection
```rust
// File: src/metrics/network.rs
pub struct NetworkMetricsCollector {
connection_metrics: ConnectionMetrics,
routing_metrics: RoutingMetrics,
dht_metrics: DHTMetrics,
security_metrics: SecurityMetrics,
}
impl NetworkMetricsCollector {
pub fn record_connection_established(&self, peer: &PeerId, duration: Duration) {
self.connection_metrics.connections_total.inc();
self.connection_metrics.connection_duration.observe(duration.as_secs_f64());
self.connection_metrics.active_connections.inc();
}
pub fn record_message_sent(&self, size: usize, encryption_type: &str) {
self.routing_metrics.messages_sent.inc();
self.routing_metrics.bytes_sent.inc_by(size as u64);
self.routing_metrics.messages_by_type
.with_label_values(&[encryption_type])
.inc();
}
pub fn record_dht_operation(&self, op_type: &str, success: bool, duration: Duration) {
let labels = &[op_type, if success { "success" } else { "failure" }];
self.dht_metrics.operations
.with_label_values(labels)
.inc();
self.dht_metrics.operation_duration
.with_label_values(&[op_type])
.observe(duration.as_secs_f64());
}
}
```
## Conclusion
This implementation plan provides concrete code examples and patterns for building the QuDAG networking layer. Each component is designed to be modular and testable, with clear interfaces between layers. The use of libp2p as a foundation, enhanced with post-quantum cryptography and anonymous routing, creates a robust and future-proof networking stack.