Cross-Chain Oracle for Bitcoin and Solana

This project implements a cross-chain oracle that bridges Bitcoin and Solana blockchains using zero-knowledge proofs (ZKPs). The oracle monitors Bitcoin ordinals and verifies them on Solana, allowing for secure and private cross-chain communication.

Table of Contents

• Prerequisites
• Setup
• Oracle Service
• Solana Smart Contract
• Client Interaction
• Testing
• Contributing
• License

Prerequisites

Ensure you have the following tools and libraries installed:

• Python 3.x
• Bitcoin Core (full node)
• Solana CLI
• Anchor Framework
• Node.js

Setup

Bitcoin Core

1. Install Bitcoin Core: Download and install Bitcoin Core from the official Bitcoin website.

2. Configure Bitcoin Core: Edit the bitcoin.conf file to enable RPC:

   server=1
   rpcuser=yourusername
   rpcpassword=yourpassword
   rpcallowip=127.0.0.1
   

3. Start Bitcoin Core:

bitcoind -daemon

Oracle Service

1. Install Required Libraries:

pip install python-bitcoinrpc pycryptodome

2. Create Oracle Service
3. Save the following code as oracle_service.py:

from bitcoinrpc.authproxy import AuthServiceProxy from Crypto.Hash import SHA256 from Crypto.PublicKey import ECC from Crypto.Signature import DSS import json

Connect to Bitcoin node

bitcoin_rpc = AuthServiceProxy("http://yourusername:[email protected]:8332")

def monitor_bitcoin_for_ordinal(ordinal_id): transactions = bitcoin_rpc.listtransactions() for tx in transactions: if ordinal_id in json.dumps(tx): return tx return None

def validate_ordinal(tx): return True # Implement your validation logic

def generate_zkp(tx): hash_obj = SHA256.new(json.dumps(tx).encode('utf-8')) key = ECC.generate(curve='P-256') signer = DSS.new(key, 'fips-186-3') signature = signer.sign(hash_obj) return key.public_key().export_key(format='DER'), signature

def send_to_solana(pubkey, signature): pass # Implement data transmission logic

ordinal_id = "specific_ordinal_id" while True: tx = monitor_bitcoin_for_ordinal(ordinal_id) if tx and validate_ordinal(tx): pubkey, signature = generate_zkp(tx) send_to_solana(pubkey, signature)

Solana Smart Contract

1. Install Solana CLI:

sh -c "$(curl -sSfL https://release.solana.com/v1.8.0/install)"

2. Install Anchor Framework:

cargo install --git https://github.com/project-serum/anchor --tag v0.19.0 anchor-cli --locked

3. Create Anchor Project:

anchor init cross_chain_oracle cd cross_chain_oracle

4. Define Smart Contract: Edit the lib.rs file in programs/cross_chain_oracle/src:

use anchor_lang::prelude::*; use solana_program::program_pack::{IsInitialized, Pack, Sealed}; use solana_program::pubkey::Pubkey;

declare_id!("Fg6PaFpoGXkYsidMpWxqSWpmyoMaMdHk4Zr1Dz4V7gAa");

#[program] pub mod cross_chain_oracle { use super::*;

pub fn verify_and_update(ctx: Context<VerifyAndUpdate>, pubkey: Vec<u8>, signature: Vec<u8>, tx_hash: Vec<u8>) -> ProgramResult {
    let pubkey = Pubkey::new(&pubkey);
    let signature = Signature::new(&signature);
    let tx_hash = sha256::Hash::hash(&tx_hash);
    require!(pubkey.verify(&tx_hash, &signature), CustomError::InvalidZKP);

    let nft = &mut ctx.accounts.nft;
    nft.metadata = "New metadata based on verified ordinal".to_string();

    Ok(())
}

}

#[derive(Accounts)] pub struct VerifyAndUpdate<'info> { #[account(mut)] pub nft: Account<'info, NFT>, }

#[account] pub struct NFT { pub metadata: String, }

#[error] pub enum CustomError { #[msg("Invalid Zero-Knowledge Proof")] InvalidZKP, }

5. Build and Deploy Smart Contract:

anchor build anchor deploy

Client Interaction

1. Create Client Script:

Save the following code as client.js:

const anchor = require('@project-serum/anchor'); const { Connection, PublicKey } = require('@solana/web3.js');

async function main() { anchor.setProvider(anchor.AnchorProvider.env()); const programId = new anchor.web3.PublicKey('Fg6PaFpoGXkYsidMpWxqSWpmyoMaMdHk4Zr1Dz4V7gAa'); const program = new anchor.Program(idl, programId); const nftPublicKey = new PublicKey('Your NFT PublicKey Here'); const response = await fetch('http://localhost:5000/get_proof'); const { pubkey, signature, tx_hash } = await response.json();

const tx = await program.rpc.verifyAndUpdate(pubkey, signature, tx_hash, {
    accounts: {
        nft: nftPublicKey,
    },
});

console.log('Transaction signature', tx);

}

main().catch(err => { console.error(err); });

Testing.

1. Deploy the Oracle Service:

python oracle_service.py

2. Run the Client Script:

node client.js License This project is licensed under the MIT License.

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