LP-6329: Teleport Bridge System Index

Abstract

This LP serves as the master index for the Teleport Bridge System, Lux Network's unified cross-chain protocol combining threshold cryptography, dedicated bridge chains, and smart contract custody. The Teleport system enables trustless, decentralized bridging between Lux Network and external blockchains including Ethereum, Bitcoin, Base, Arbitrum, Optimism, and Cosmos IBC chains. A single MPC-generated address works across all EVM-compatible chains, with threshold signatures (CGG21 for ECDSA, LSS for dynamic resharing, FROST for Schnorr, and Ringtail for quantum-safe extensions) ensuring no single party controls bridged funds. This index provides navigation to all related LPs, summarizes system architecture, and serves as the entry point for understanding the complete bridge infrastructure.

Motivation

The Teleport Bridge System spans multiple LPs covering threshold cryptography, bridge operations, key management, and smart contract integration. Navigating this complex documentation requires a central index that provides a high-level overview of the system architecture, lists all component LPs, and explains how they relate to each other. This informational LP serves as the entry point for developers, auditors, and users seeking to understand or implement cross-chain bridging on Lux Network.

System Overview

+-------------------------------------------------------------------------+
|                         Lux Network Chain Architecture                   |
+-------------------------------------------------------------------------+
|                                                                         |
|  MAINNET CHAINS (Live):                                                 |
|  +-----------------+  +-----------------+  +-----------------+          |
|  | P-Chain         |  | X-Chain         |  | C-Chain         |          |
|  | Platform        |  | Exchange        |  | Contracts       |          |
|  | Validators,     |  | UTXO Assets,    |  | EVM, Gnosis     |          |
|  | Native Multisig |  | Native Multisig |  | Safe (LP-0335)  |          |
|  +-----------------+  +-----------------+  +-----------------+          |
|  +-----------------+  +-----------------+  +-----------------+          |
|  | Q-Chain         |  | T-Chain         |  | B-Chain         |          |
|  | Query/Index     |  | ThresholdVM     |  | BridgeVM        |          |
|  |                 |  | MPC Signatures  |  | Cross-chain     |          |
|  |                 |  | (LP-0330)       |  | (LP-0331)       |          |
|  +-----------------+  +-----------------+  +-----------------+          |
|                              |                    |                     |
|                              +--------+-----------+                     |
|                                       |                                 |
|                              +--------v---------+                       |
|                              |  External Chains |                       |
|                              | ETH, BTC, Base,  |                       |
|                              | Arbitrum, Cosmos |                       |
|                              +------------------+                       |
|                                                                         |
|  EXPERIMENTAL:                            SPECIFICATION (RFC):          |
|  +-----------------+  +-----------------+  +-----------------+          |
|  | A-Chain (AIVM)  |  | Z-Chain (ZK)    |  | K-Chain (KMS)   |          |
|  | Mainnet: flag   |  | Devnet only     |  | LP-0336 RFC     |          |
|  | Devnet: default |  |                 |  +-----------------+          |
|  +-----------------+  +-----------------+  | I-Chain (DID)   |          |
|                                           | RFC pending     |          |
|                                           +-----------------+          |
+-------------------------------------------------------------------------+

Chain Legend:
- P,X,C,Q,T,B: Live at mainnet launch
- A,Z: Experimental (A behind flag on mainnet, Z devnet-only)
- K,I: Specification phase, seeking RFC approval
- No T-Chain: P-Chain/X-Chain provide native multisig
- No Relayers: B-Chain validators handle cross-chain observation

Component LPs

Mainnet Chains (Live at Launch)

Chain	Description	Multisig Support	Status
P-Chain	Platform chain for validators, chains, staking	Native N-of-M multisig for governance	Live
X-Chain	Exchange chain for UTXO-based transfers	Native UTXO multisig	Live
C-Chain	EVM-compatible contract chain	Smart contract multisig (Gnosis Safe)	Live
Q-Chain	Query/Index chain	Standard	Live
T-Chain	Threshold signatures (ThresholdVM)	MPC threshold signatures	Live
B-Chain	Bridge operations (BridgeVM)	Decentralized cross-chain	Live

Experimental Chains

Chain	Description	Availability	Status
A-Chain	Application chain (AIVM)	Devnet default, Mainnet behind experimental flag	Experimental
Z-Chain	Zero-Knowledge proofs chain	Devnet only	Experimental

Specification Phase (Seeking RFC)

LP	Chain	Description	Status
LP-0336	K-Chain	KeyManagementVM - ML-KEM post-quantum encryption, secrets management	RFC
TBD	I-Chain	Decentralized Identity chain (DID/Verifiable Credentials)	RFC
LP-0325	-	HSM Integration (8 providers, PKCS#11)	Draft

Teleport Bridge Chain Specifications

LP	Title	Description	Status
LP-0330	T-Chain ThresholdVM	All MPC/threshold operations: DKG, signing (CGG21, FROST), resharing (LSS)	Draft
LP-0331	B-Chain BridgeVM	Bridge operations: deposits, withdrawals, cross-chain observation via validators	Draft

Protocols

LP	Title	Description	Status
LP-0332	Teleport Architecture	Complete cross-chain bridge protocol specification	Draft
LP-0333	LSS Dynamic Rotation	Validator-integrated signer rotation without key reconstruction	Draft
LP-0334	Per-Asset Keys	Independent threshold configurations per bridged asset	Draft

Integration

LP	Title	Description	Status
LP-0335	Smart Contract Integration	Bridge contracts (Vault, Router, Registry) with MPC signatures	Draft
LP-0339	Security Procedures	Operational security, incident response, key rotation	Draft
LP-0340	Bridge SDK	Client libraries for TypeScript, Go, and Rust	Draft
LP-0341	Secrets Management	Decentralized secrets management with HSM	Draft

Architecture Notes

Multisig: Traditional n-of-m multisig is handled natively by P-Chain and X-Chain. For C-Chain, Gnosis Safe is the recommended approach. Threshold cryptography (where no single party holds the complete key) is provided by T-Chain.

Relayers: Bridge relayer functionality (external chain observation, fee funding, transaction execution) is fully integrated into B-Chain's BridgeVM via the RelayerRegistry. Relayers register with B-Chain and earn fees for executing cross-chain transactions.

Foundation LPs

LP	Title	Description
LP-13	T-Chain MPC Custody	Original MPC custody and swap signature layer
LP-14	CGG21 Threshold ECDSA	UC non-interactive threshold ECDSA with identifiable aborts
LP-103	LSS Protocol	Linear Secret Sharing with dynamic resharing
LP-104	FROST	Flexible Round-Optimized Schnorr Threshold Signatures

Architecture Summary

T-Chain (ThresholdVM) - LP-0330

The T-Chain provides threshold cryptography services:

Algorithms: CGG21 (ECDSA), FROST (Schnorr/EdDSA), LSS (resharing), Ringtail (quantum-safe)
Key Management: Per-key threshold configuration, dynamic signer sets
Operations: DKG (KeyGenTx), signing (SignRequestTx/SignResponseTx), resharing (ReshareTx)
Security: Identifiable aborts, proactive refresh, Byzantine fault tolerance

// T-Chain managed key structure
type ManagedKey struct {
    KeyID        KeyID              // "eth-usdc", "btc-native"
    PublicKey    []byte             // Aggregated public key (constant across reshares)
    Algorithm    SignatureAlgorithm // CGG21, FROST_SCHNORR, FROST_EDDSA
    Threshold    uint32             // t: minimum signers required
    TotalParties uint32             // n: total parties holding shares
    PartyIDs     []party.ID         // Current signer set
    Generation   uint32             // Incremented on reshare
}

B-Chain (BridgeVM) - LP-0331

The B-Chain orchestrates cross-chain operations:

Operations: Deposits, withdrawals, cross-chain swaps
State Management: Pending transactions, confirmations, execution tracking
Chain Support: EVM (Ethereum, L2s), Bitcoin (Taproot), Cosmos (IBC)
Security: Multi-relayer observation, fraud proofs, daily limits

// B-Chain bridge state
type BridgeState struct {
    PendingDeposits    map[DepositID]*DepositRecord
    PendingWithdrawals map[WithdrawID]*WithdrawRecord
    PendingSwaps       map[SwapID]*SwapRecord
    AssetRegistry      map[AssetID]*AssetInfo
    ChainStates        map[uint64]*ChainState
}

Teleport Architecture - LP-0332

The unified protocol specification covers:

Deposit Flow: External chain deposit -> relayer observation -> B-Chain confirmation -> T-Chain signature -> C-Chain mint
Withdrawal Flow: C-Chain burn -> B-Chain request -> T-Chain signature -> external chain release
Cross-Chain Swaps: Atomic operations with signature coordination
Fee Distribution: Validator (50%), relayer (20%), treasury (20%), burn (10%)

Dynamic Signer Rotation - LP-0333

LSS-based rotation without key reconstruction:

Reshare Protocol: Old signers generate subshares for new signers using Lagrange interpolation
Generation Tracking: Monotonic generation numbers with atomic activation
Triggers: Validator changes, proactive refresh, emergency rotation
Rollback: Safe reversion to previous generation on failure

Generation 0: Parties A, B, C (2-of-3)
     |
     | ReshareTx(newParties=[A, B, D, E], threshold=3)
     v
Generation 1: Parties A, B, D, E (3-of-4)  <- Same public key!

Per-Asset Key Management - LP-0334

Independent threshold configurations:

Asset Tier	Threshold	Parties	Latency	Use Case
Micro (<$1K)	2-of-3	3	<150ms	Retail payments
Small ($1K-$10K)	2-of-3	3	<200ms	Standard transactions
Medium ($10K-$100K)	3-of-5	5	<400ms	Business transactions
Large ($100K-$1M)	4-of-7	7	<600ms	Institutional
Custody (Cold)	7-of-11	11	<2s	Treasury reserves

Smart Contract Integration - LP-0335

Five core contracts for on-chain bridge operations:

BridgeVault: Asset custody with MPC signature verification (EIP-712)
BridgeRouter: Transaction routing with fee calculation
TokenRegistry: Cross-chain asset mapping
BridgeGovernor: Timelocked parameter governance
EmergencyBrake: Circuit breaker for security incidents

Network Configuration

Mainnet Deployment

Component	Endpoint/Address	Chain ID
LUX C-Chain RPC	`https://api.lux.network/ext/bc/C/rpc`	96369
T-Chain RPC	`https://api.lux.network/ext/bc/T/rpc`	-
B-Chain RPC	`https://api.lux.network/ext/bc/B/rpc`	-
LUX Teleporter	0x5B562e80A56b600d729371eB14fE3B83298D0642	96369
ETH Teleporter	0xebD1Ee9BCAaeE50085077651c1a2dD452fc6b72e	1
Base Teleporter	0x37d9fB96722ebDDbC8000386564945864675099B	8453
Arbitrum Teleporter	0xA60429080752484044e529012aA46e1D691f50Ab	42161

Testnet Deployment

Component	Endpoint/Address	Chain ID
LUX Testnet RPC	`https://api-test.lux.network/ext/bc/C/rpc`	96368
T-Chain Testnet	`https://api-test.lux.network/ext/bc/T/rpc`	-
B-Chain Testnet	`https://api-test.lux.network/ext/bc/B/rpc`	-

Node Requirements

Component	CPU	RAM	Storage	Network
Full Node	8 cores	32 GB	500 GB NVMe	100 Mbps
Validator/Signer	16+ cores	64 GB	1 TB NVMe	1 Gbps
HSM (mainnet)	-	-	-	Required

Configuration

{
  "network": {
    "chainId": "T",
    "rpcPort": 9630,
    "stakingPort": 9631
  },
  "mpc": {
    "threshold": 3,
    "totalParties": 5,
    "protocol": "cgg21",
    "refreshEpochBlocks": 43200
  },
  "keys": {
    "bridge-main": {
      "protocol": "lss",
      "threshold": 3,
      "parties": 5,
      "curve": "secp256k1"
    }
  }
}

Quick Start Guide

1. Running a Teleport Node

# Build the node
cd ~/work/lux/node
./scripts/build.sh

# Start with Teleport chains enabled
./build/luxd \
  --network-id=96369 \
  --vm-aliases='{"B":"bridgevm","T":"thresholdvm"}' \
  --threshold-config='{"threshold":3,"totalParties":5}' \
  --http-port=9630 \
  --staking-port=9631

2. Joining the Signer Committee

# Register as threshold signer
curl -X POST http://localhost:9630/ext/bc/T/rpc \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "threshold_joinCommittee",
    "params": {
      "partyId": 1,
      "stakeProof": "0x...",
      "publicKey": "0x..."
    }
  }'

3. Initiating a Bridge Transfer

import { BridgeRPCClient, ThresholdRPCClient } from '@luxfi/bridge-sdk';

const bridgeClient = new BridgeRPCClient({
  endpoint: 'http://localhost:9630/ext/bc/B/rpc',
});

// Deposit ETH to Lux
const { depositId } = await bridgeClient.initiateDeposit({
  token: '0x0000000000000000000000000000000000000000',
  amount: '1000000000000000000', // 1 ETH
  destChainId: '96369',
  recipient: '0x...',
});

// Monitor status
const status = await bridgeClient.getBridgeStatus(depositId);

4. Requesting a Threshold Signature

# Request signature from T-Chain
curl -X POST http://localhost:9630/ext/bc/T/rpc \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "threshold_sign",
    "params": {
      "keyId": "eth-usdc-bridge",
      "messageHash": "0x7f83b1657ff1fc53b92dc18148a1d65dfc2d4b1fa3d677284addd200126d9069",
      "messageType": "RAW_HASH",
      "deadline": 1000
    }
  }'

Repository Map

Repository	Description	Path
github.com/luxfi/node	T-Chain (ThresholdVM), B-Chain (BridgeVM) implementations	`~/work/lux/node`
github.com/luxfi/bridge	Bridge monorepo (SDK, relayer, UI)	`~/work/lux/bridge`
github.com/luxfi/threshold	Threshold cryptography (CGG21, LSS, FROST, Ringtail)	`~/work/lux/threshold`
github.com/luxfi/crypto	Core cryptographic primitives	`~/work/lux/crypto`
github.com/luxfi/mpc	MPC signer daemon and protocols	`~/work/lux/mpc`
github.com/luxfi/sdk	Client SDKs (TypeScript, Go)	`~/work/lux/sdk`

Key Source Files

node/vms/thresholdvm/
├── vm.go                   # ThresholdVM implementation
├── state.go                # State management
├── tx/
│   ├── keygen.go           # KeyGenTx
│   ├── sign_request.go     # SignRequestTx
│   ├── reshare.go          # ReshareTx
│   └── ...
├── protocol/
│   ├── cggmp21/            # CGG21 implementation
│   ├── frost/              # FROST implementation
│   └── lss/                # LSS resharing

node/vms/bridgevm/
├── vm.go                   # BridgeVM implementation
├── state.go                # Bridge state
├── tx_deposit.go           # Deposit handling
├── tx_withdraw.go          # Withdrawal handling
└── watchers/
    ├── evm_watcher.go      # EVM chain observer
    └── btc_watcher.go      # Bitcoin observer

threshold/
├── protocols/cmp/          # CGG21 protocol
├── protocols/frost/        # FROST protocol
├── protocols/musig2/       # MuSig2 for Bitcoin
└── protocols/ringtail/     # Quantum-safe signatures

Roadmap

Phase 1: Specifications (Current)

Phase 2: Mainnet Launch

Chains Live at Launch: P-Chain, X-Chain, C-Chain, Q-Chain, T-Chain, B-Chain

Phase 3: Experimental Features

A-Chain (AIVM) - behind experimental flag on mainnet, default on devnet
Z-Chain (ZK) - devnet only initially
Ringtail quantum-safe signatures

Phase 4: RFC Implementations

K-Chain (KMS) - post RFC approval
I-Chain (DID) - post RFC approval
External security audits
Bug bounty program

Phase 5: Expansion

Glossary

Term	Definition
CGG21	Canetti-Gennaro-Goldfeder-Makriyannis threshold ECDSA protocol with UC security and identifiable aborts
DKG	Distributed Key Generation - protocol for creating shared keys without trusted dealer
FROST	Flexible Round-Optimized Schnorr Threshold signatures for EdDSA/Schnorr
Generation	Version number of a threshold key's share distribution (increments on reshare)
LSS	Linear Secret Sharing - resharing protocol enabling signer rotation without key reconstruction
MPC	Multi-Party Computation - cryptographic techniques for distributed computation
Reshare	Process of redistributing key shares to new signer set while preserving public key
Ringtail	Lattice-based post-quantum threshold signature scheme
T-Chain	Threshold Chain - dedicated chain for threshold cryptography operations
B-Chain	Bridge Chain - dedicated chain for bridge operation coordination
Threshold (t)	Minimum number of signers required to produce a valid signature
Total Parties (n)	Total number of signers holding key shares
Warp Message	Cross-chain message protocol within Lux Network

Security Model

Threat Model

Adversary Capabilities:

Can corrupt up to t-1 signer nodes
Can observe all network traffic
Can delay (but not drop) messages
Has full control over corrupted nodes

Security Goals:

Unforgeability: Cannot forge signatures without t shares
Key Secrecy: Cannot learn private key from fewer than t shares
Liveness: Protocol completes if t honest parties participate
Identifiable Abort: Misbehaving parties can be identified and slashed

Slashing Conditions

Violation	Penalty	Evidence
Invalid share	10% stake	VSS verification failure
Commitment mismatch	20% stake	Commitment != H(response)
Double signing	50% stake	Two valid shares for same session
Offline during session	5% stake	No response before deadline
Key material exposure	100% stake	Signature analysis proof

Teleport Bridge System Index