GSTD Cross-Chain Bridge

Trustless GSTD token transfers between TON, Solana, and XRPL.
Written in Rust. Runs as a lightweight validator node alongside GSTD Node OS.

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What It Does

The bridge lets you move GSTD tokens freely between chains — no custodians, no central relayers. A decentralized set of validators watches all three chains simultaneously. When a deposit is detected, validators reach consensus (67% quorum), aggregate their MPC threshold signatures, and release funds on the destination chain.

Lock on source → Quorum consensus → MPC sign → Unlock on destination

No single party can steal funds. No single party can stop a transfer.

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Architecture

┌─────────────────────────────────────────────────────┐
│                   GSTD Bridge Node                  │
│                                                     │
│  ┌──────────┐  ┌──────────┐  ┌──────────┐          │
│  │TON Watch │  │SOL Watch │  │XRP Watch │           │
│  └────┬─────┘  └────┬─────┘  └────┬─────┘          │
│       └──────────────┼──────────────┘               │
│                      ▼                              │
│            ┌─────────────────┐                      │
│            │ Consensus Engine │◄── libp2p Gossipsub │
│            │   (67% quorum)  │                      │
│            └────────┬────────┘                      │
│                     ▼                               │
│            ┌─────────────────┐                      │
│            │   MPC Signer    │ threshold signatures  │
│            └────────┬────────┘                      │
│                     ▼                               │
│            ┌─────────────────┐                      │
│            │  Vault Manager  │ lock / unlock         │
│            └────────┬────────┘                      │
│                     ▼                               │
│            ┌─────────────────┐                      │
│            │   RPC Server    │ → Node OS / Frontend  │
│            └─────────────────┘                      │
└─────────────────────────────────────────────────────┘

P2P Network

• Discovery: Kademlia DHT — validators find each other automatically
• Messaging: Gossipsub — proposals and votes propagate to all validators
• No bootstrap server required — validators connect via known peer multiaddrs (fetched from app.gstdtoken.com/api/v1/nodes/peers)

Consensus

• Threshold: 67% of active validators must approve a transfer
• Timeout: 10 minutes — expired proposals are discarded
• Double-spend protection: Transfer IDs are globally unique (hash of tx_hash + chain + recipient)

MPC Threshold Signatures

Private keys are never held by a single party. The signing key is split across validators using threshold cryptography (t-of-n). Even if t-1 validators collude, they cannot sign anything.

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Vault Addresses

Chain	Vault	Explorer
TON	EQDv6cYW9nNiKjN3Nwl8D6ABjUiH1gYfWVGZhfP7-9tZskTO	tonscan.org
Solana	AzN7uPhQZgThxsRvhNGHPUPRjdEjScTbqQdf5gt6Fqby	solscan.io
XRPL	ryHSvxUqpcTjoESHbCkMJoqzenjFgPQSf	xrpscan.com

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Bridge Protocol

How to Bridge

1. Send GSTD to the source chain vault with memo:

   bridge:<target_chain>:<recipient_address>
   

2. Example — TON → Solana:

   bridge:solana:AzN7uPhQZgThxsRvhNGHPUPRjdEjScTbqQdf5gt6Fqby
   

3. Wait for 3 confirmations on source chain (~15-30 seconds on TON)

4. Validators detect deposit, reach quorum, release funds on destination

5. Total bridge time: ~2 minutes (depends on validator count)

Bridge Fees

• 0.1% flat fee on bridged amount
• Fee is split among validators who signed the transaction
• Minimum fee: 1 GSTD (to cover gas on destination chain)

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Running a Bridge Validator

Running a bridge validator earns you a share of bridge fees.

Prerequisites

• Rust 1.75+
• 1GB RAM, 10GB disk
• Stable internet connection (the bridge node must be reachable)
• Small balance of TON, SOL, and XRP for gas (outgoing transactions)

Quick Start

# Install
git clone https://github.com/gstdcoin/gstd-bridge
cd gstd-bridge
cargo build --release

# Generate config
./target/release/gstd-bridge --init

# Edit bridge.toml — add your RPC endpoints and wallet keys
nano bridge.toml

# Start
./target/release/gstd-bridge

# Or with Docker
docker build -t gstd-bridge .
docker run -v $(pwd)/bridge.toml:/app/bridge.toml gstd-bridge

Config (bridge.toml)

[node]
data_dir = "./data"
keypair_path = "./data/keypair"

[p2p]
listen_addr = "/ip4/0.0.0.0/tcp/9000"
bootstrap_peers = []  # Auto-fetched from app.gstdtoken.com/api/v1/nodes/peers

[chains.ton]
rpc_url = "https://toncenter.com/api/v2"
vault_address = "EQDv6cYW9nNiKjN3Nwl8D6ABjUiH1gYfWVGZhfP7-9tZskTO"
api_key = ""  # Optional toncenter API key

[chains.solana]
rpc_url = "https://api.mainnet-beta.solana.com"
vault_address = "AzN7uPhQZgThxsRvhNGHPUPRjdEjScTbqQdf5gt6Fqby"

[chains.xrpl]
rpc_url = "wss://xrplcluster.com"
vault_address = "ryHSvxUqpcTjoESHbCkMJoqzenjFgPQSf"

[consensus]
quorum_threshold = 0.67
transfer_timeout_secs = 600

[mpc]
share_index = 0           # This validator's key share index (0-based)
threshold = 2             # Minimum signatures required
total_parties = 3         # Total validator count
key_share_path = "./data/key_share.bin"  # Persisted Ed25519 key share

[rpc]
listen_addr = "127.0.0.1:9001"

Become a Validator

1. Run the bridge node
2. Register your node via the GSTD Platform
3. Stake 10,000+ GSTD (Provider tier) in the NaaS registry
4. The DAO votes to add you to the active validator set

With 3+ validators online, the bridge is live.

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RPC Endpoints

The bridge node exposes a local HTTP API:

Endpoint	Method	Description
/api/bridge/status	GET	Node status, peer count, uptime
/api/bridge/transfers	GET	Recent bridge transfers
/api/bridge/transfer/:id	GET	Single transfer details + votes
/api/bridge/vaults	GET	Vault balances per chain

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Module Structure

src/
├── main.rs             # Main event loop
├── config.rs           # Configuration (TOML)
├── p2p/
│   ├── mod.rs          # libp2p Swarm (Kademlia + Gossipsub)
│   ├── gossip.rs       # Gossipsub message handler
│   └── discovery.rs    # Kademlia DHT
├── chains/
│   ├── mod.rs          # ChainMonitor trait
│   ├── ton.rs          # TON watcher (toncenter API)
│   ├── solana.rs       # Solana watcher (RPC)
│   └── xrpl.rs         # XRPL watcher (WebSocket)
├── consensus/
│   ├── mod.rs          # Voting engine (67% quorum, timeout, dedup)
│   └── state.rs        # Shared transfer state table
├── mpc/
│   ├── mod.rs          # Threshold signature scheme
│   └── keygen.rs       # Distributed key generation
├── bridge/
│   ├── mod.rs          # BridgeMessage enum (Gossipsub payloads)
│   └── vault.rs        # Lock/Unlock vault accounting
└── rpc/
    └── mod.rs          # Axum HTTP server

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Security Model

Threat	Mitigation
Single validator colludes	MPC threshold — needs 67% to sign
Validator goes offline	Transfer requeued after timeout, other validators continue
Double spend	Transfer ID is globally unique, consensus records prevent replay
Vault drain	On-chain contracts enforce lock logic; only valid MPC sig unlocks
Network partition	Gossipsub retries + Kademlia rerouting; quorum drops gracefully

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Ecosystem

Repo	Description
gstdcoin/contracts	Smart contracts (TON vault, NaaS staking)
gstdcoin/gstdbot	Node OS (bridge runs alongside it)
gstdcoin/ai	Platform dashboard
gstdcoin/gstd-bridge	This repo — bridge validators

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License

MIT