Ghost Pay

Fast, private Bitcoin payments. Lock once, send freely, settle anytime.

Overview

Ghost Pay is a Layer 2 payment system built on Bitcoin. Unlike Lightning, it doesn't require managing channels, finding routes, or worrying about liquidity. The mental model is simpler:

1
Lock
Lock Bitcoin once on L1. This creates your spending capacity.
→
2
Send
Send instant private payments. Confirms in ~10 seconds.
→
3
Settle
Settle back to Bitcoin anytime. Your keys, your coins.
Key Principle
Ghost Pay always settles to Bitcoin. There's no "Ghost coin" or separate token. You're always holding Bitcoin — just in a form that can move faster and more privately.

Fees

Ghost Pay charges a flat 0.1% fee on payments. This fee is split between the Treasury and Node Reward Pool using the same control decay ratio as the mining pool fee. After ossification, 100% of Ghost Pay fees go to the Node Reward Pool.

How It Works

Locking Funds

To use Ghost Pay, you first lock Bitcoin into a vault. This is a special Bitcoin transaction that:

  • Commits your funds to the Ghost Pay system
  • Creates a UTXO that can only be spent according to vault rules
  • Defines your maximum spending capacity

The locking transaction is a standard Bitcoin transaction — it confirms on L1 like any other.

Sending Payments

Once locked, you can send payments instantly:

  1. You create a payment to a Ghost address
  2. The payment is signed with multi-party signatures
  3. The payment is recorded in a microblock
  4. The microblock is anchored to Bitcoin via a commitment

Payments confirm in ~10 seconds. The recipient can spend immediately.

Receiving Payments

Receiving is even simpler:

  • Share your Ghost address (or generate a stealth address)
  • Payments arrive automatically
  • You can receive even while offline
  • Claim payments when you reconnect

Settlement

When you want to move funds back to regular Bitcoin:

  1. Request a settlement
  2. The vault closes with a Bitcoin transaction
  3. Your funds appear at your Bitcoin address

Settlement takes ~10 minutes (one Bitcoin confirmation).

Ghost Pay vs Lightning

Ghost Pay and Lightning solve the same problem differently:

Feature Lightning Ghost Pay
Channels Required (open/close) Not needed
Routing Find path through network Direct to recipient
Inbound Liquidity Required to receive Not needed
Online Requirement Must be online to receive Receive while offline
Payment Failures Common (routing issues) Rare (direct path)
Privacy Limited (onion routing) Strong (stealth addresses)
Max Payment Limited by channel Limited by vault
Complexity High Low
Not a Lightning replacement
Ghost Pay and Lightning serve different use cases. Lightning excels at micropayments and has a larger network. Ghost Pay focuses on simplicity and privacy. They can coexist.

Vault Channels

Vaults are the core primitive of Ghost Pay. A vault is a programmable Bitcoin UTXO with specific spending rules.

Vault Structure

Vault { capacity: 1.0 BTC // Maximum funds balance: 0.75 BTC // Current balance owner: pubkey // Your public key state_root: hash // Merkle root of state spend_paths: [ cooperative_close, // Both parties agree unilateral_close, // Timeout + proof penalty // Fraud detected ] }

Vault Types

  • Personal Vault — Single-owner, for spending
  • Shared Vault — Multi-party, for business/escrow
  • Merchant Vault — Optimized for receiving many payments

QTxIn / QTxOut

Ghost Pay uses structured transaction descriptors:

  • QTxOut — Describes a vault's on-chain representation
  • QTxIn — Describes how a vault can be spent

These allow full reconstruction of vault state from on-chain data.

Multi-Party Signatures

Ghost Pay uses multi-party signing to ensure state integrity:

  • All parties must agree to state transitions
  • No "half-signed" or inconsistent states are possible
  • Revocation is cryptographically enforced
  • Based on secp256k1 ECDSA signatures

How It Works

  1. Sender proposes a payment
  2. All affected parties sign the new state
  3. Old state is cryptographically revoked
  4. New state becomes the only valid state

If anyone tries to publish an old state, the penalty path activates and they lose funds.

Privacy Features

Ghost Pay is private by default:

🔒
Silent Payments
Every payment creates a unique stealth address. No address reuse, no tracking.
👻
Hidden Amounts
Payment amounts are hidden using Bulletproof zero-knowledge proofs. Only parties involved can see values.
🌐
No Graph Analysis
Payments don't create traceable on-chain links. Settlement batches obscure individual payments.
📴
Offline Receive
Receive payments without being online. No information leaked about your online status.
Privacy vs Compliance
Ghost Pay provides strong privacy but is not designed for illegal use. Users can voluntarily disclose transaction details for compliance. The goal is privacy by default, transparency by choice.

Settlement

Ghost Pay uses BUDS-tagged commitments to anchor state to Bitcoin:

Anchoring Methods

  • segOP (if adopted) — Structured TLV lanes in segregated data
  • OP_RETURN — Fallback using standard OP_RETURN outputs

Microblocks

Ghost Pay batches many payments into microblocks:

  • Microblocks are off-chain state transitions
  • Many microblocks are summarized into a single commitment
  • Commitments anchor to Bitcoin periodically
  • Full state can be reconstructed from Archive nodes

Settlement Types

Type Time Use Case
Cooperative Close ~10 minutes Normal settlement, all parties agree
Unilateral Close ~1 week Counterparty unresponsive
Penalty Close Immediate Fraud detected (old state published)

Development Status

Ghost Pay is currently in development. The roadmap:

Phase Status Description
Specification Complete Protocol design finalized
Reference Implementation In Progress Core libraries being built
Testnet Planned Testing on Bitcoin testnet
Mainnet Future Production launch

Ghost Core and Ghost Pool launch first. Ghost Pay follows once the node network is established.

Not Required
Ghost Pay is optional. You can run a Ghost node and mine without ever using Ghost Pay. It's an additional feature for those who want fast, private payments.