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@ Brunswick
2025-05-18 04:14:48Abstract
This document proposes a novel architecture that decouples the peer-to-peer (P2P) communication layer from the Bitcoin protocol and replaces or augments it with the Nostr protocol. The goal is to improve censorship resistance, performance, modularity, and maintainability by migrating transaction propagation and block distribution to the Nostr relay network.
Introduction
Bitcoin’s current architecture relies heavily on its P2P network to propagate transactions and blocks. While robust, it has limitations in terms of flexibility, scalability, and censorship resistance in certain environments. Nostr, a decentralized event-publishing protocol, offers a multi-star topology and a censorship-resistant infrastructure for message relay.
This proposal outlines how Bitcoin communication could be ported to Nostr while maintaining consensus and verification through standard Bitcoin clients.
Motivation
- Enhanced Censorship Resistance: Nostr’s architecture enables better relay redundancy and obfuscation of transaction origin.
- Simplified Lightweight Nodes: Removing the full P2P stack allows for lightweight nodes that only verify blockchain data and communicate over Nostr.
- Architectural Modularity: Clean separation between validation and communication enables easier auditing, upgrades, and parallel innovation.
- Faster Propagation: Nostr’s multi-star network may provide faster propagation of transactions and blocks compared to the mesh-like Bitcoin P2P network.
Architecture Overview
Components
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Bitcoin Minimal Node (BMN):
- Verifies blockchain and block validity.
- Maintains UTXO set and handles mempool logic.
- Connects to Nostr relays instead of P2P Bitcoin peers.
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Bridge Node:
- Bridges Bitcoin P2P traffic to and from Nostr relays.
- Posts new transactions and blocks to Nostr.
- Downloads mempool content and block headers from Nostr.
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Nostr Relays:
- Accept Bitcoin-specific event kinds (transactions and blocks).
- Store mempool entries and block messages.
- Optionally broadcast fee estimation summaries and tipsets.
Event Format
Proposed reserved Nostr
kindnumbers for Bitcoin content (NIP/BIP TBD):| Nostr Kind | Purpose | |------------|------------------------| | 210000 | Bitcoin Transaction | | 210001 | Bitcoin Block Header | | 210002 | Bitcoin Block | | 210003 | Mempool Fee Estimates | | 210004 | Filter/UTXO summary |
Transaction Lifecycle
- Wallet creates a Bitcoin transaction.
- Wallet sends it to a set of configured Nostr relays.
- Relays accept and cache the transaction (based on fee policies).
- Mining nodes or bridge nodes fetch mempool contents from Nostr.
- Once mined, a block is submitted over Nostr.
- Nodes confirm inclusion and update their UTXO set.
Security Considerations
- Sybil Resistance: Consensus remains based on proof-of-work. The communication path (Nostr) is not involved in consensus.
- Relay Discoverability: Optionally bootstrap via DNS, Bitcoin P2P, or signed relay lists.
- Spam Protection: Relay-side policy, rate limiting, proof-of-work challenges, or Lightning payments.
- Block Authenticity: Nodes must verify all received blocks and reject invalid chains.
Compatibility and Migration
- Fully compatible with current Bitcoin consensus rules.
- Bridge nodes preserve interoperability with legacy full nodes.
- Nodes can run in hybrid mode, fetching from both P2P and Nostr.
Future Work
- Integration with watch-only wallets and SPV clients using verified headers via Nostr.
- Use of Nostr’s social graph for partial trust assumptions and relay reputation.
- Dynamic relay discovery using Nostr itself (relay list events).
Conclusion
This proposal lays out a new architecture for Bitcoin communication using Nostr to replace or augment the P2P network. This improves decentralization, censorship resistance, modularity, and speed, while preserving consensus integrity. It encourages innovation by enabling smaller, purpose-built Bitcoin nodes and offloading networking complexity.
This document may become both a Bitcoin Improvement Proposal (BIP-XXX) and a Nostr Improvement Proposal (NIP-XXX). Event kind range reserved: 210000–219999.